that's a bit rich. They offer My SciTech PE (Personal Edition) for free use, where they'll generate a driver supporting 1 chipset however it doesn't have an option for VESA VBE 2.0, which is what Parallels presents to the guest OS. I tried generating one anyway on the off chance they would fall back to VESA mode, but they don't.
I've dropped them a note asking if they'll sell a 1 user license or if they'll add VESA as an option for My SciTech PE.