The prototype was built on a TA22 GT chassis with frame number TA22-026004. This was originally built in May 1971 as a Celica TA22 GT coupe. The mechanicals of the TA22 GT were retained (1600cc 2T-G twincam engine).
The front of the interior was the same as the TA22 GT except for a different fabric pattern on the seats. Electric window lifts were used (optional but rare on the TA22 GT) but the TA22 GT's optional air conditioning was not present.
The rear 2 seats were individually reclining using the same reclining hinges and latches as the front seats except that the rear latches were in the middle. A centre padded vinyl console was between the 2 rear seats and the seat belts clipped into it when not in use. The spare tyre sat vertically at the very rear of the cargo area under a vinyl cover.
The SV-1 had a rear fuel filler similar to the early coupes. Toyota changed all Celicas to side fuel fillers in mid 1972, so all production liftbacks had fuel fillers on the left rear quarter panel with a cover flap.
The SV-1 rear hatch glass was a bit larger than the production version. The key hole for the hatch was on the beaver panel (it was on the hatch on production liftbacks). The grill was an ST type - just like all 1973-1975 production liftbacks (even the GT models). Dual exhaust tips exited out the rear (production Celicas had a single exhaust tip). An electric aerial was put in the left rear quarter (the TA22 had this on the left front wheel guard).
The RV-1 (a prototype 2 door wagon based on the Celica coupe) with the Marinetta boat and trailer was also shown at the 1971 Tokyo Motor show but did not reach production.