NP Mate, you called it as you see it.
The Regupol stuff is a roofing/insulation rubber mat that is fairly cheap. Its made of old tires grinded up and pressed together. Its has an increddible low maintenence level due to the open structure of the stuff. Dust doesn't gather on it so you'll only have to vacume it 2 or 3 times a year. The usage started in Sweden where by now all tracks (atleast the ones i know of) switched to using it. We'll start using it in a couple of weeks (Belgium). The guys in Sweden pay only 5Euros (about 6.5$) per sqaure meter. About 3sqaure foot i think. Our track (12x5m) (38x16 foot) would cost us 300-350 Euros (390-450$).
I know there is a company in the US or Canada that sells it wholesale, but i'm sure it can be found at large DIY centres.
Regards