PSYCHOPHD lets trade man! hahaha jk. I'm from SoCal too, and man the s2000 has been my dream car since it came out MY2000.
Anyways, everyone's post before mine have pretty much summed up what I would have said. But just a few pointers.
1. Simple bolt ons will give you significant hp/tq gains. All I have so far is a short ram intake and an upgraded intercooler, that's actually enough for me, although I might do a downpipe eventually (unless of course we traded =D).
2. Shifter is just ok on this car, but what do you expect from a cable driven shifter/fwd car. I have the aftermarket rear MM to help with the engine movement, but it won't completely fix the engine from bucking if you plan on driving it like you stole. Otherwise you should be fine on a daily driving basis.
3. Engine mounts - I hear people complain both 07 and 08 models, but i've had my car for the past 21,xxx miles and 0 problems.
4. Smoking turbos - again 0 problems on my end, but people talk about it.
5. Don't let that sales person try to tell you that you have to buy the aftermarket parts in order for it to be covered. That's a whole lot of crap. Granted, there are certain rules as far as how the warranty is covered with aftermarket Mazdaspeed parts, but I think the guy is just trying to pressure you into buying those parts now. I have non mazda aftermarket parts, and my warranty has not been voided...but then again I haven't brought it in for any engine work.
Oh and the car you went to see, was it used or new? I wouldn't be surprised if Mazda Corp doesn't have any incentives right now because of the economy, but if his dealership does, I would inquire about it...and maybe push them for more
...so good luck...and let me know if a trade would even cross your mind (2thumbs)...I don't have kids so i don't need the extra room, just the fun factor