Let the hive mind of Engadget get that for you.
"We need a digital camera that can be switched on and fire off that first shot fast. It's not a commonly tracked statistic on any review site, and nobody seems to have this information for every camera. We were hoping other readers could inform us as to what small digital cameras can fire off their first pics in under a second (ideally under half a second). It needs to be small, but mostly, just really quick in operation. Thanks!"
If Garmin were to add this to their DNX8120 which is a coventure with Kenwood, I would buy this cable thing. I have been looking at doing something similar using a HKS Camp 2 or Magden M.1b to get video gauges despite the fact that without USB touchscreen capability, user interface functionality is limited to remote control and that I would have to install this via the reverse monitor input.