Ozite racing carpet is sold in bulk rolls exclusively through CRC.
Our club has run on commercial low-pile carpet for years and it actually lasts longer, but is a little more squishable...so the pancar guys get kinda grumpy cuz their cars 'dance' around under heavy cornering, etc...but you should really run on what ya got, not complain about the track conditions.
Most automotive interiors are made from Ozite-fiber carpet...but you will only find the bulk rolls from CRC. RCMits has a great pic there of what I'm speaking of...however, I have NEVER run on ANYTHING that has more fiber detachment (getting those hairy things on your car) than Ozite...it's just plain horrible, but it is the standard for indoor R/C racing.