I've never had a truck with a warranty, so modding the truck has never been a problem for me.
But, being a college student with hardly any money, and the wife also going to school at the moment, having a warranty for the car is a must. If something (major) happened to the truck, right now we probably couldn't afford to fix it, so the car would be the only thing we would have.
After I get a job, however, I plan on making enough to never have to worry about the warranty on any vehicle I own. Cause I'm gonna be banking. Big. Dude. I also plan on getting the impala tuned as soon as I graduate and get a real job. Cause it needs to wake up some.