Zeta, I appreciate the advice. So it seems the 2011 Regal Turbo and 2012 Sonata Turbo are not worth taking to the track, at least without some sort of racing tires.
Well, the tires aren't really the problem. A Vette or a Miata would be fine on any tires. The cars you have are very big and heavy and front wheel drive and the suspension is soft and designed to lean toward understear. If you put race tires on it then you'd just learn how easy it is to roll the car. 
Consider a CTS or a 5 series if you want big powerful and track worthy. Your cars are much more designed for comfort, long cruises, and getting decent fuel economy, and from what I understand they are very good at that. Meanwhile my Miata gets only 26 MPG and the wind noise is even worse than the rattling interior.
Apparently I bought a terrible car, my Regal Turbo only gets 16.3 MPG and I can't even play with it on a track. I am sure the fact I only do city driving kills it though and you are right that it is very comfortable.
Final question (for real). If you have an all-wheel drive vehicle, would that be usable on a track? Or is only a rear wheel drive car appropriate? I honestly would love to get on a track and play around, but living in Buffalo, NY rear-wheel drive isn't really an option (unless you want 2 cars, which I don't). I was thinking of an ATS when I upgrade to my next car, but I would definitely get the all-wheel drive variety. If that isn't track ready, then I guess my dreams of being a racer will never come true!
As far as I can tell, everyone thinks the turbo Regal is really great. It just isn't a performance car. No matter what the numbers say, no matter what the salesman said. Its a quality passenger sedan, it just has completely different priorities.
When the G8 came out GM made a big deal about how on paper it was as good or better than a 5 series in every way. To some extent I agree with them. That is, if you drive both and you literally cannot tell why the 5 is worth more money, more maintenance costs, dealer-only fleecings, etc, then by all means buy the G8. If you can't see why the 5 is better then you would be wasting your money. Anyone who has owned a string of BMWs isn't going to go for that though.
And the G8 was a friggn' Pagani Zonda compared to the Regal.
BTW, 16.8 MPG is f*cking ridiculous. Are you running E85 or something? That's exceptionally bad. That's worse than my '93 Chevy pickup than I only do winter city driving with.
As for FWD/AWD/RWD. I assume by mentioning that you live in Buffalo you are thinking that RWD doesn't work in snow. This isn't true at all. We get just as much snow in Michigan, so does Germany, and I assure you Ann Arbor is swimming in BMWs, Mercedes, Porsches, and pick-up trucks year round. With modern day suspension, tire, and traction control technologies there is no reason for a safe driver in a well maintained car to fear snow. Now, a Mustang with a broken ABS sensor and summer-only tires? He's f*cked.
As for on the track, neither is inherently superior. There are plenty of high performance FWD cars that can clean my clock like GTIs, Intengras, Mini Coopers S, Abarth 500s, etc. The main difference between those cars and what you have though is about 1000lbs of mechanical flab.
Small and FWD is fine, big and FWD is not good for the track. A performance-oriented AWD system is an advantage, but only if you have the power to push it along. A WRX or Evo will fly with AWD, but it just slows down an Audi TT or Ford Taurus. I honesty think that AWD has outlived its usefulness in anything but off-road oriented applications or extreme performance supercars. FWD is the most practical, RWD is the most fun.
