Marlin used Monstaliner on his VX and found that it was brittle too IIRC. Seems like he had a few chunks fall off as well, so I believe he just used a pressure washer to blast it all off and then used Showroom New. He's a lot happier with that product the last I heard.
Just throwing it out there... and btw Showroom New is a LOT cheaper than the $134 you need for Monstaliner. It won't, however, have the texturing which depending on your taste may be a good or bad thing.