just bought a 2008 HHR 1/2 panel and cant understand how it still smells new.
is there something that the dealers do?

 

If the previous owner didn't eat in it or manage to get the carpets wet, it can very much still smell new.

 

I have a 1987 Chevy Silverado that still smells new. Really. The trick is to keep the interior dry, be sure that you don't leave porous materials inside (clothes, towels, rags) that can retain moisture and keep the windows closed. I have done this for 23 years. I have friends that sometimes open the door just to sample the new car smell of the '80's.

The HHR that you are referring to was probably kept this way by luck.