You guys are hilarious but I have to admit this very humiliating fact: I actually did ponder buying some kind of 10-second timer thing and wiring that in series to the 12-volt Autopulse so when I turn the key/pull the "pump" switch the thing would make the clacky-clack noise.
We rightly complain here all the time about shoddy Chinese knock-offs and such, but one thing this little endeavor has brought home (again) is the sheer betterness of new stuff. Each of those Autopulse 500s weighs about as much as a loaded Colt 45. And they leaked notoriously. And, at the time, these were aircraft parts.
The Carter, by contrast, weighs as much as an empty water pistol, costs about the same and reportedly never leaks. You look at stuff like this and wonder how anyone managed to hotrod anything back in the day.
Those guys were doing 180 mph down the Mulsanne driving absolute rubbish: 600-lb straight-sixes lit by Lucas electrics. Bloody drum brakes! The mind just boggles.