[jeffgrice]

The major improvements on the RT4 over the RT3 include

Improved and stiffened chassis. Completely redesigned

Safer chassis (side impact protection) with better reinforcement to the outer body.

Metal floors instead of fiberglass

Fully adjustable BMW suspension

Improved sawyer geometry

Far better ride

Far better handling

Additional passenger compartment room

Additional driver compartment room

Wider seats

Drop drivers side floor for additionally leg room and through the windshield visibility

Limited slip Ford Motorsports differential now standard