Please help me improve my site's design.. :(

Hello. Please help me.

Something seems off in my Pontiac Grand Am site's design.

The header/logo area, IMO, looks fantastic, but below that it all seems boring.
What can I do to make it look better?

I'm not sure what to do...I just know that it looks really off at the moment.

This should be in gallery showcase.
Anyway, there isn't enough content, so all the place is empty and looks boring.
Try making the content are smaller or fill it up a bit.
Also the sidebar is a bit to simple.
It's like you stoped working on it once the header was done.