Just a thought. I don't know what all would be involved with using a marine setup on a car, but the thought has crossed my mind a few times after seeing them at my engine builder's shop over the years.
http://cgi.ebay.com/ebaymotors/Mercruiser-EFI-MPI-Multi-Port-Injection-454-system-502-_W0QQitemZ390091911074QQcmdZViewItemQQimsxZ20090909?IMSfp=TL0909091710008r904
Tommy