New owner of a 2012 GT

[Nybiomed]

...got it for $22.5k with the remote starter, dimming rear view mirror/ compass, bumper guard and wheel locks. I immediately got a Inno roof rack w/ ski attachment, tinted the windows, upgraded the sound system and Dynamatted most of the car. It really needed these upgrades and I feel exactly as others have stated that this is the way the GT should have come from the factory! Speakers are truly pitiful and weigh a meager 6.5ounces each. I had Infinity 2-way 5x7s installed with a Kenwood 4ch amplifier powering them, much better now, but I'm going to install the SoundStream USB-8a powered subwoofer under the front passenger's seat (if there's room) when it arrives from EBay next week. I think road intrusion is still pretty high, but I also have these knobby-azzed Nokian Hakkapellittas 2's on the corners I picked up from Craigslist, coupled with the roofrack, so I'm a bit forgiving...I've been playing with some interior LED lighting too.
After talking with the installer, I might upgrade the head unit to the Kenwood DNX 9980HD as it has everything... The installer said the OEM head unit has pretty weak output and lousy dynamic range, I don't know the full truth of what he's saying, but looking at the OEM speaker reinforces his opinion-. I'll re-evaluate after the 8" powered sub is installed; but I do want in dash navigation and I could get a Refurbed Kenwood unit off EBay for $575...I had to listen to the stereo at level 40 while driving 70mph just to hear it sound like crap before the upgrade, now it sounds halfway decent at level 30 while traveling 70.
The M5 is starting to display a moderate vibration at 70mph which is getting annoying. I had the rims balanced after the 4 Dorman TPMSs were installed- $100 from RockAuto.com, but it hasn't gone away, so I might take it in to Mazda...Ive the feeling that they'll want the OEM 17" Toyos back on though and there's a lot of winter left up here in the mid-Hudson Valley, NY, so I might wait until April....
I just broke 2k miles and plan on doing the first oil change at 3k miles with the larger Purolator Pure1 filters and oil from Advance Auto Jan deals.

 

[ukulele]

Let me be the first to welcome you to the forums!! I will also be the first to welcome you to the wonderful world of Mazda's vibration problems!!

It's a known issue, Mazda is aware of it as well, the 2012s with the 17 inch wheels/tires (Touring and Grand Touring) may experience a vibration that comes through the steering wheel, between 40MPH and up to 75MPH. There is another guy on here by the name of "mether" and he had the same thing, as I have the same thing. They can balance the wheels all day long, won't help one bit. I had to actually write Mazda a certified letter and demand one last repair attempt before going to Lemon Law here in my state (NJ).

They had their "regional" Mazda tech come down and look at the problem. He basically swapped the 17 inchers for 16 inchers either from a Mazda5 sport or a Mazda3. He then stated on the repair work order, and I quote, "Vehicle runs rough on 17 inch TIRES" and I capitalized the word tires because that is very important, you see, Mazda has been pointing the finger at Toyo, you probably have Toyo Proxes A18 tires. After this final repair attempt which really didn't repair anything, I called up Toyo, they said they would warranty all 4 tires but the dealer has to call them to open a P.O. Toyo will send the dealer 4 new tires (same ones, the Proxes A18, they can't change them for another series or model tire) and they will also pay for balancing.

I still have the vibration but it's reduced somewhat with the new Toyos. For reference, while I was waiting for my Mazda5 to be fitted with new rubber, I test drove a 2013 Mazda5 with the Toyo Proxes A18 tires, it was a GT, and it too had a tendency to vibrate on the highway, though not as pronounced as my problem was.

Funny thing is, you said that you have taken off the Toyos and you still have the vibration which leads me to believe it's not the tires at all. I still have up to 24k miles or 24 months to complete the Lemon Law application, but I'm waiting on some other stuff.

As far as the audio system, yeah, it's pretty weak. When warmer months come, I will be adding an external amp to the factory system, I'm keeping the factory unit, just looks better I think, and chaining the speaks for real ones. I might add a capacitor with LEDs and voltage readout just for a light show, though I don't know where a lot of this stuff is going to go because there isn't much room to begin with.

 

[Nybiomed]

Let me be the first to welcome you to the forums!! I will also be the first to welcome you to the wonderful world of Mazda's vibration problems!!

It's a known issue, Mazda is aware of it as well, the 2012s with the 17 inch wheels/tires (Touring and Grand Touring) may experience a vibration that comes through the steering wheel, between 40MPH and up to 75MPH. There is another guy on here by the name of "mether" and he had the same thing, as I have the same thing. They can balance the wheels all day long, won't help one bit. I had to actually write Mazda a certified letter and demand one last repair attempt before going to Lemon Law here in my state (NJ).

They had their "regional" Mazda tech come down and look at the problem. He basically swapped the 17 inchers for 16 inchers either from a Mazda5 sport or a Mazda3. He then stated on the repair work order, and I quote, "Vehicle runs rough on 17 inch TIRES" and I capitalized the word tires because that is very important, you see, Mazda has been pointing the finger at Toyo, you probably have Toyo Proxes A18 tires. After this final repair attempt which really didn't repair anything, I called up Toyo, they said they would warranty all 4 tires but the dealer has to call them to open a P.O. Toyo will send the dealer 4 new tires (same ones, the Proxes A18, they can't change them for another series or model tire) and they will also pay for balancing.

I still have the vibration but it's reduced somewhat with the new Toyos. For reference, while I was waiting for my Mazda5 to be fitted with new rubber, I test drove a 2013 Mazda5 with the Toyo Proxes A18 tires, it was a GT, and it too had a tendency to vibrate on the highway, though not as pronounced as my problem was.

Funny thing is, you said that you have taken off the Toyos and you still have the vibration which leads me to believe it's not the tires at all. I still have up to 24k miles or 24 months to complete the Lemon Law application, but I'm waiting on some other stuff.

As far as the audio system, yeah, it's pretty weak. When warmer months come, I will be adding an external amp to the factory system, I'm keeping the factory unit, just looks better I think, and chaining the speaks for real ones. I might add a capacitor with LEDs and voltage readout just for a light show, though I don't know where a lot of this stuff is going to go because there isn't much room to begin with.

Yes, I replaced the stock 17" wheels with the 16" Nokians and have noticed the problem develop over the last 1500 miles or so, I cannot recall if the problem existed B4?...I will eventually have to put the OEM wheels back on to determine whether the issue is intrinsically with the M5 and not the aftermarket wheelset. I had hoped that when the Dorman TPMS sensors were installed/balanced last week, the vibration would cease- I put the snow tires from Craigslist on within 10 days of buying the M5, and did not have the wheels balanced at that time because I was unwilling to pay the $300 STS tire wanted for the sensors....below 60MPH you really cannot feel the vibration. Did your vibration develop over time- is it more prominent now than when you first drove your M5 off the lot? Could it have something to do with the braking system- as the rotors/lugnuts are part of the rotation assembly that doesnt really ever get balanced.
Unless the aftermarket integrated Navi/Head unit looks factory I probably wont get it done, but my installers made a phone call and said a faceplate is available for a seamless double-DIN look- a single DIN just doesn't look right IMO...truthfully tho, how much would it have cost Mazda to do what I have done to the GT, perhaps another $125? It cost me about $1000 for everything.