Stretch

the Stretch is a lincoln town car limo

Stinger & Yakuza Stinger

the Stinger and the Yakuza Stinger are the same, and so is the convertible Stinger, but they are all very original. They look very much like the new Pontiac Solstice Club Racer, but that wasn't out when the game was made.

Securicar

just an armored trucks with a giant, solid grille.

Pony & Panlantic & Toyz Van

a hightop american company van

Mr. Wongs & Mule & Belly-Up Fish Van

just a small, old international box truck.

Mr Whopee

The ice cream van seems like it could be a Toyota Hiace with the ice cream van stuff, but at the same time, it just looks like any rounded cab-before-wheels van.

Moonbeam

The moonbeam is a rounded out Chevy Astro, with a dash of Mitsubishi Expo/ Colt Vista.