When I was a PSO, I helped design a rocket recovery system that went on to create a small crater in Lincolnshire[1]. The basis of the design was that nobody on the rocket team could obtain the relevant licence to use explosive bolts (rocket, for the breaking in half so the parachute could deploy), so we came up with a novel spring-loaded mechanical system to sproing the drogue chute out the back (it worked well in the lab, but we suspect didn't react well to either high G-forces, or proximity to rocket exhaust).
I forget the details, but it was a right pain. And that was pre-9/11.
(The actual solid-fuel rocket motor stuff was all handled by the grown-up rocket scientists who organised the competition, and presumably dealt with testing military stuff-wot-goes-BOOM on a regular basis.)
Mocking up a RPG-vs-car for the telly would presumably also require someone licenced to muck about with pyrotechnics, but presumably that's a bit easier to come by. You can probably tell by whether it looked like a high explosive (bang, shrapnel, bit of smoke) or the slow flamey smokey explosion that Hollywood has taught us to expect. Although if I were filming the real thing, I'd probably spice it up with a liberal distribution of petrol in unsuitable containers.
[1] I wanted to work on the electronics, but they put me with the parachute guys. Not surprising that the final-stage recovery ended up being done with a spade, and while the other team that actually made it to launch also crashed, they won by default because our telemetry didn't work.