When the Angels return to the Townsend Agency after ditching their chaperones, the exterior shot shows all three of their cars parked outside - including Kelly's recently destroyed Mustang, in pre-explosion condition.
In the opening scene, what appears to be a combo of a '60s Mustang and mid-70s Mustang II is used in place of Kelly's Mustang II, and is blown up. Also, detonator cables can be seen leading to the passenger side door.
When the Angels are driving up to Antonia's mansion, the camera pulls back from the parked Rolls Royce (while the producer credit is onscreen) and a crew member's head pops in, out, and back into the frame in the lower right corner. Then, as the camera pans left and Kris parks the car (while the writing credits are onscreen), something - likely the shoulder of another crew member - comes into the frame at left and quickly exits.