how do i get out of it without being rude

This is a good point, rani. While YOU might not care about your old cars, believe it or not, some people might. Such as perspective employers. If you pull in somewhere for an interview in (in their eyes) some old POS, it could have an effect. Like it or not, people judge on the things they can see first. By contrast, if you whoop up in a bright shiny new car, they might see responsibility. It can work to your advantage in certain instances. You shouldn't be so dead set against it. Let your parents do it for you. They will not be here forever and it will give the a sense they are needed.

I have NEVER had any employer care what I drove to an interview in...in fact, most of them didn't know.