Our former Professions section editor, Bob Bellinger, had heated seats in his Alfa Romeo. First and only time I experienced that uxury despite growing up in Michigan.
Anyway, you got to be a pretty bold hacker to start messing with your care electronics. Its a complex next of interrelated stuff. I had a Fiat in college and once one electrical subsystem went out there was a cascading set of problems that led to be junking it.
I was hoping that this blog post was going to be about adding a seat warmer to a car. My 2011 Ford Escape didn't come with that option, and let's just say it's mightly cold on those leather seats in January!!!