TravelLite™ Seat Cushion by Lifeform®
Product Review (submitted on September 28, 2012):
I drive 2 hours round trip to work each day and developed terrible tailbone pain. This seat cushion fixed the problem after several weeks of use by removing the tailbone cutout. Would recommend this seat to anyone. Takes a little getting used to sitting up a little higher in your seat if you are tall but well worth the money. Still looks brand new after a year of use.