All BT's have a metallic finish. The Alts have flat finishes. Be careful when buying an BT as the first release (smokescreen) had horrendous paint chippinf issues. I stick to my $20 Alts instead. Hopefully all of the colorschemes will be released as Alts and not just BT's. Here's a couple more Alts for ya:
Ravage (speculation) - http://community.webshots.com/album/190475745spfgpJ
Honda S2000 (unnamed) - http://www.tfans.com/index.php?showtopic=9017
Grimlock - http://www.walmart.com/catalog/product.gsp...duct_id=3129558