what kind of car was it?

Most of the factory cars were Fiat Regatas, there were a few Fiat 127s mixed in (the small two-door hatchbacks in the scene where Saito and Sakamoto are counting to 15,000 cars. A mistake IMO- the 127 was launched in 1971 and far too dated to pass for a new 1986 model Japanese-designed car as most of those had a complete model change every 4 years then.)

The cars the Assan executives arrive in are Dodge Omnis or Plymouth Horizons (only difference between the two was the grille, these were disguised with "Assan" grilles. I wonder if this was a pickup shot filmed after the Fiats were re-exported or destroyed because of nonconformance with U.S. EPA and NHTSA rules)

Finally, a Dodge Charger (then-current FWD model, the coupe version of the Omni) was used on the poster and the original VHS boxart.

*The only true currency in this world is what you share with someone else when you're uncool.*