Replying to Road trip through America ideas.

Hello America!

Next year some time (probably July or August) some friends and I are coming to your country to experience the joys you have to offer. Basically, we plan to fly into LA, buy a car - we have a friend who lives there to help us out - and fly out of New York 6 - 8 weeks later.

We only thought of this trip the other day so excuse any ignorance or flaws in our plan, but I thought I'd ask some real Americans who live in America about things to do.

So while this is still in its planning phase I'm here for your opinion:
must see towns/places, things to see/do that a guide book or google couldn't tell me etc etc.

So please throw some suggestions my way.

Thanks.