With Transformers 4 on the way, not only would Bay redesign some of the autobots but he will be sure enough to include new ones as well as the decepticons. To make things interesting here is a very cool selection of vehicles and aircrafts for the robots of the 4th intallment to transform into:
Autobots
Optimus Prime as a Peterbilt 379
Sentinel Prime as a Rosenbaum Firetruck 316
Override as a Red Buick Enclave
Bumblebee as a Yellow and Black Strip Camero
Trailbreaker as a Black Chevy Avelanche
Hound as a Green Jeep Wrangler
Sideswipe as a Silver Chevrolet Correvette
Ratchet as a Green Search and Rescue Hummer
Ultra Magnus as a Mobile Missile Launcher
Powerglide as an A-10 Warthog
Springer as a V-22 Osprey
Moonracer as a Blue Porsche Cayenne
Silverbolt as a Lockheed C-130 Hercules Gunship
Skydive as a MIG-29
Fireflight as a F-15 Fighterjet
Slingshot as a Google Jet
Sky Shadow as a Curtiss XF-87 Black Hawk
and Omega Supreme as The Ark
and the
Decepticons
Skyquake as a B-1 Lancer
Blitzwing as a F-35 Lightning and a Merkava Mk4 Battle Tank
Cyclonus as a F-117 Nighthawk
Scourge as a B-2 Bomber
Octane as a Black Dragon like Gas Tanker and a Black Private Jet
Dirge and Thrust as F-22 Raptors
Onslaught as a Mobile Missile Launcher
Vortex as a UH-60 Blackhawk
Swindle as a Military Hummer Jeep
Blast Off as a F-16 Fighter Jet
and Treadshot as a Leclerc Main Battle Tank
There you have it folks, the best alternate modes for the autobots and decepticons that Michael Bay should use to make Transformers 4 the best of the entire film series!