How to Decorate Son's Room When It Has Textured Walls

You can put the cars posters in those large plastic frames and hang them up. Or, be cheap like us and just thumbtack them in (we also have a cars poster in my boys room). The decals wont work though.

You can make a big paper chain with matching colors and tack them like a garland on the walls. You can hang a car themed pinata.

You could take black duct tape and make like a speed way on a wall, paint a dotted line in yellow down the center, then hot glue small hot wheels or foam cars on it like they are racing on a speedway.

You can get cheap racing flags or banners at a party store and pin them on the walls.

Lots of cute ideas here:
http://www.google.com/search?hl=en&q=car+themed+room&...

3M picture hanging strips are a renter's best friend! They are easy to use, come in different strengths and pull off easily.

This is just an idea, but we have magnetic paint. Its black, but you can paint white right over it if you have white walls. That way you can decorate a lot and not mar the walls.

How about thumbtacks for his posters, border paper, wall decals?
Tape posters to back of door, closet doors etc.