Rumrunn, this is my rain jacket, I do believe it's high collared... the top edge of the collar just narrowly misses my base of the skull, I would think this is considered high collar?
http://www.chainreactioncycles.com/M...x?ModelID=9268

After taking a look... it seems that something like Showers Pass' Rain Hood could do the job too, at only 25 USD!
http://www.rei.com/product/793730

Until I get it, I think I'll stick to the shower cap method... just that the mirror mount makes it a tricky fit...

Thanks folks for your input... keep them coming!