a vehicle in which the frame and body are one unit
the car's rigid unibody
b.
(as modifier)
a unibody construction
Their pick-up was the first vehicle in its class with a unibody construction insteadof a body-on-frame design.
unibody in American English
(ˈjunəˌbɑdi)
adjective
designating or of a type of construction used in motor vehicles in which the floor, roof, panels, etc. are welded together into one unit, thereby eliminating the need for a separate frame