Just read some of the car descriptions on Vehicles in Grand Theft Auto V | GTA Wiki | Fandom
“The 190z is a dual combination of the Datsun 240Z/Nissan Fairlady Z/Nissan S30 and Toyota 2000GT”
“The Cheburek is a mix of various models of Lada Classic lineup. Its sides resemble the trimless sides of the VAZ-2101 while the front end is borrowed from the VAZ-2106. The rear is extremely similar to that of the Datsun 510, but relevant to the Lada line of cars is closer to the VAZ-2101 but with minor changes such as more detailed taillights and a rear mounted licence plate light instead of a bumper mounted light.”
“The car’s design heavily resembles the Ferrari Testarossa, with elements of the Ferrari 512 BB from its taillights and frontal area and also elements of the Ferrari 288 GTO from its fog lights, hood and air vents behind the rear wheels.”
GTA remixes various real world cars into a unique designs. The same is done with weapons. Lamborghini has a much harder time suing for copyright infringement if the back of the car looks more like a Ferrari. And then Lamborghini would have to be able to claim then own those design queues, which likely wouldn’t hold up in court, because a lot of design is inspired and referenced by other cars, and it’s hard to label any part of a design as completely unique.