After the scene where Vic is walking Lacy and Sadie out of the crime scene, the next shot briefly shows Lacy's "stolen" 280Z parked outside her apartment. The car drives by after she and Vic leave the apartment.
When Lacy parks her car at the beginning of the movie, it is a 2+2 model (4 seats) that has a longer wheelbase. The car that blows up later in the movie is a 2 seat model with a shorter wheelbase, showing a different car was used for this part of the movie. The car that blows up has no motor. This is apparent due to the front end of the car sitting noticeably higher than earlier in the movie. Additionally, there is a mark or damage on the driver's door after the explosion that was not on the other car.
The goof item below may give away important plot points.
The manner shown in which the person is shot is nearly impossible. Holding a handgun in one hand outside a car window reduces the accuracy (no line of sight or aiming is possible) and at the distance shown it is unlikely a human sized target could be hit.