Jabberwocky79 is correct , white walls are not on any car but the 32 ford. If you saw them on line id be interested in seeing the video , post a link please. As for the locked parts can you take a picture of the parts that are locked . This will show us what is locked specifically and what the message you get IS when trying to use the parts. If you see the lock symbol it will also tell you want you need to do in order to unlock that parts. Exhaust for example can be done by completing a certain amount of speed trap events i believe. Just finishing the story mode doesn't unlock everything. Follow what the games telling you to do in order to unlock the parts my friend .