I've used an electric leafblower for car drying in the past, but currently use the Metro Vacuum SK-1 Sidekick due to garage/driveway space constraints. The filtered/warmer air helps, plus I bought the extension hose for better control. I'd prefer the larger, more powerful units they make, but I wanted something a bit more portable.
I've also used the CR Spotless system (bought from Costco online) but changing the media got sort of tiresome after a while. I think forced-air drying is the better option overall. I find the drying process therapeutic.