if it's for off camera then anything that doesn't have a standby mode (or one that kicks in after a long time).
End of the day light is light, if you're paying big money you'll get iTTL or eTTL adjustable zoom, bounce card and say 1/3 stepping for power output
As you're using it off camera, you don't need metering, and if it's too powerful you choke it (umbrella) or move it further back, if it's not powerful enough you move it closer

Generally a more expensive flash will have a large guide number (brighter) but odds are for automotive you wont be on full power (unless you start using soft boxes or large umbrellas).
I use Nissin Di622 but I've modded mine, so that the hotshoe still triggers the flash in slave (optical trigger stock) mode. The 466 is generally considered better if you aren't handy with a solder, as they don't have a standby mode in non-slave mode.