And the winner is...
Fergy. It is, indeed, an HO car-but in the
real HO scale of 1:87(ish) rather than 1:64(ish)
Runners-up were:
Astro for originality
Mr M for guessing the intended fate of the little bugger
It's a Galoob MicroMachines Testarossa.
I was looking at it to caniballise for whatever ARII kit I can find (or an Airfix Bugatti with full interior) and thought it might run on the Scaley track. I just jammed a couple of bits of desolder braid under the original shoes and zzzip! It'll keep up with most of my other cars and is nearly a second quicker than the SCX Minardis.