after thinking about it tonight, i've pretty much made up my mind where i'm going with this...
i want a data logger anyway, so going to buy the aimsports data/logger w/ 2 cameras... will use 2nd camera for forward looking view... it has a sensor that automatically starts the video, perhaps it could be programmed to display only when in R for the street-going folks?
AiM Sports - DaVid Video and Data Logging system for Race Cars - Create a DVD of your on-track performance!
for display, i'm either going to go with a rear view mirror kit (like the one on new mustang that's gotten really good reviews)...
rear view mirror display - Google Product Search
... or... this is prob a pipe dream... perhaps I can convert the clock on the 3 gauge cluster to a small display... i'll look into it