how do i get out of it without being rude

Accept the car. You're lucky to have such wonderful parents, although the fact that you're adopted says much about their character already. It really sounds like they're concerned with your safety and security, not judging your love of old cars.

In my experience, driving my new car makes me appreciate my old cars. And driving my old cars sometimes makes me (gasp) appreciate what new cars have to offer. The way I see it, it's like using the right tool for the job. Much as I love my old Mopars, there are times when I need a quiet, reliable, gas-sipping set of wheels. A new Dart might also fit the bill. ;) It wouldn't be my first choice, but there's obvious love in the fact that they picked a new Dart. It makes me want to give 'em a big hug!

Either way, congrats! Post some picks if you accept their offer!