The DMC DeLorean DMC-12 is a sports car designed and sold in the early 1980s - it's well known for being the time machine in the Back to the Future film series. It's widely known as simply the DeLorean, as it was the only vehicle the company ever produced.
It's connection to the Resident Evil series is that it makes an appearance in
Resident Evil 2 and Resident Evil 3. It's most likely that it's inclusion is because somebody on the team really liked the car or the movie franchise, and created the 3D model and just HAD to use it somewhere, as an Easter Egg.
In
Resident Evil 2, it can be seen near the beginning of the game, parked outside the Delicatessen. The car is pristine and gleaming, unlike all the other cars shown in the area - which shows the zombies probably appreciated it as well.
In Resident Evil 3, the car is seen at the gas station but this time with broken windows and no longer clean. It has a USA flag draped over it's roof.
It's most likely the same vehicle, as
Resident Evil 2 and Resident Evil 3 take place in Raccoon City and overlap at points. It's unknown what actually transpired, but the most likely story is that somebody saw the car outside the delicatessen and drove it to the gas station in an attempt to re-fuel, crashed the car and escaped (or became infected).
The car is not seen in any other game, including the Remakes.