Old Character New Alt Mode

He drops Stratosphere, a truck, out of his cargo bay to fight Demolishor.

Got your back there, LCDR.

If starscream was to be a car it would have to be the Lanborghini Reventon. The Reventon was styled after the F22, and since Starscream was an F22 in the movies, it makes perfect sense (IMO)

You know how G1 had triple changers and BW had Fuzors but they've never had triple changer beasts (Transmetals don't count because their second alt mode isn't a second animal) or a fusion of two different vehicles. Well...

Springer would have an Armadillo and a humming bird alt mode.

Broadside would have a hawk and a whale alt mode.

Sandstorm would have a scorpion alt mode which he's already been but he'd still be a triple changer with a second vulture alt mode to go with that whole desert theme there.

Astrotrain... well his name won't make any sense but I'm doing it anyway... A horse and a Tardigrade. Check out this video if you don't know what that is and then suddenly this will make sense. Tardigrades: Adorable Extremophiles - YouTube

Blitzwing would have a hawk and spitting raptor alt modes. Not sure what the actual name of them is, they're the guys with the things that fold up on the side of their heads and they spit poison.

Octane would be an octopus because it fits his name and bird eating spider. Again fits his name.

BW Silverbolt as a fusion between a gray hound bus and a the original Silverbolt's jet mode. He'd have the body and rear wheels of the bus but he'd have the jet's engines and tail wings in the back and of course the main wings and in place of the front wheels is just the jet's front landing gear.

Quickstrike would be a fusion of a Shelby Cobra and a Scorpion Battle tank. He'd basically be a car with a tank cannon sticking out of the back.

your "Spitting Raptor" as you call it, is called Dilophosaurus. And it was only like that in Jurassic Park (Fossil Evidence doesn't Show that Dilos had frills or structures onto which the frills could attach)

Strarscream: F 18 Hornet
Skywarp: 19 (Stealth Fighter, make him more of a Sword Fighter, given his Teleportation Power)
Thundercracker: Some Heavily Armed Fighter (mix of the A 10 and F 22)
Lugnut: Russian Hind (Mi 24/ 25)

Tailgate as a pickup truck.

Kup as a Ford Explorer
Bumblebee as an ATV
Starscream as a White, Red, and Blue Yakolev Yak-141 (Rusky VTOL)
Skywarp as a Black and Violet Harrier Jump Jet
Thundercracker as a Blue and Black F-35 (F-22 With VTOL capabilities)
Topspin as a MiG-21
Twintwist as a Tunnel Boring Machine

I forgot someone before when I was talking about Fuzors... probably because he wasn't actually labeled as a Fuzor but being that he's Tigerhawk he does fit the characteristics of a Fuzor so it should still count.

So, again, name won't make sense, but take the Dawn of the Future's Past versions of Tigatron and Airrazor and fuse them together. Basically making a convertible with wings and a jet engine. And true to his toy, not really his character model, you can have an optional twin canopy/nose cone section that covers the front of the convertible. Of course with the canopy up the only thing left of the car would be the tires.

The Fallen as a Stan Lee/Simon Furman Triple-changing Pretender