Well yeah, that was the very end of that thing. Here's the setup to that last part:
After he smacked his wife with a fire poker and stuffs her body into the trunk, he get's pulled over the first time by that cop who tells him to follow him to a gas station that's still open where he can get a new bulb. When they get there, the mechanic/attendant puts the bulb in but it doesn't work, and so the cop tells him to open the trunk so the mechanic can check the wiring. The killer then walks up to get the keys out of the ignition and pulls the trunk key off his keyring and drops it between the seats and walks back to the back of the car where the cop and mechanic are waiting and tells him he can't find the trunk key. The persistant cop then says that the machanic can jimmy the tnuck open with a crowbar, and which time the killer says he doesn't want to damage his car just for this and then hits the tail light with his fist at which time the tail light starts working. The cop then tells the killer that he's lucky but he better have the thing checked out the next day, which the killer agrees to just to get away from the situation and he drives off. And then thinking he's "Dodged" a bullet(pun intented here), the killer continues down the road to the lake to dispose his wife's body, BUT the killer had given the attendant 10 bucks for the bulb which cost only 25 cents, and because the change of $9.75 coming back to the killer was considered a lot of money back in 1950s, the cop, being an honest and forthright servant of the public good, chases down the killer to give him his change, whereupon we finally get to the ending of the show which you saw, and whereupon the cop now insists that the killer now follow him to the police station so police mechanic on duty can open up the trunk with his set of skeleton keys to see why the tail light had quit working again.
(...and the "exciting conclusion" is something that is left to the audience's imagination, which is something that is now apparently out-of-fashion in today's world where everything and every action is now blantantly expressed on screen to much less sophisticated generation!!!)
