I've been at the front now for 10 minutes and the printer is crazy. It's super slow, it doesn't print out some numbers, it prints duplicates of others, the poor staff are at a loss, oy . . .
Try V&A waterfront? Nice and close to the endpoint of the race. Don't know how many other racers park here, as last year we took the train, but we're giving it a try this time since we plan to do after-race food and drink at the waterfront. http://www.waterfront.co.za/Documents/map_print_parking.pdf