I think this is the company Grigg was thinking of.

Gulfway Insurers,
12701 US Hwy 19
Bayonet Point, FL 34667

1-800-940-5010 www/racensur.com

Don't know any thing about them except several members of the ATHS seem to use them. I think they are geared toward the larger trucks such as semi-s. There is no mileage restriction.
All of the above info came from the November/December
Wheels of Time