Theoretically, it would work because the foil creates a faraday cage around the device which blocks the signal. The big flaw with that is that you would have to wrap and unwrap it every time you want to get in or leave your car.
Mine isn't great either right now. But, 90% or more of my driving is my commute to work and back in rush hour traffic. Plus, cold Canadian winters don't help. My average speed is usually close to 20 km/hr and includes lots of warm up time and idling time. I am usually sitting at about 11 l/100...
I had trouble with that my ffirst few weeks. I think the problem was me. I havent had it happen in six months now. I close the door gently from the ridge by the mazda symbol on the hatch and it always closes now. For me it was just getting used to the electronic latch.
The most important place for you to put it is over the whole grill area. Cover the entire front of the car including, and especially, the rad vents. Otherwise you get bugs in there. You also need to put some over your air filter so it stays clean longer. Also, to reduce emissions, fill the hole...
The seat warmers retain the previous setting when the car is started. I set mine on low when winter started and haven't had to touch the button since. :)
You are not the only one who has driven cars without awd and without winter tires. We pretty much all have. I had for 15 years. Awd with winter tires or fwd with winter tires is significantly better. There is no comparison, especially with both. Saying that people who use winter tires and or awd...