Signatures:
The signatures that'll get you the biggest money.
Shia
Megan Fox (these BOTH need to sign)
Peter Cullen (Transformers "nuts" will go crazy for this one). He did the voice of Optimus and he's the original voice of Optimus.
Also Michael Bay (remember though, a lot of "Transformers-fans" don't like the fact that Michael Bay did the movie...but those people probably wouldn't have interest in a "Camaro-Bumblebee")
Jon Voight and John Turturro (they're pretty big names but I don't think they'd bring in the buyers since they weren't the main actors) (Reminds me of a Seinfeld episode..."THIS CAR ONCE BELONGED TO JON VOIT!"
)
Another thing to remember: This isn't really "Hollywood Memorabilia" because it was never actually ON SCREEN.