+1We have one of these from Snap-On:
BK6000, Borescope, Recording, Video/Still
Takes snapshots and video and the heads are interchangeable... In our case we have the standard straight head, a dual head (straight and side-looking), as well as a UV head (for chasing leaks when using tracer dye). Easily one of the best investments I ever made and especially useful on a car like the M5 where everything is hidden away (especially the parts that commonly leak).
At my work we had the Rigid one, it was alright, the head was a little to big to fit in thru spark plug holes, and no picture taking ability made it useful maybe a handful of times.
We actually picked up the same Snap-On one you have, and its awesome. I used it to diagnose a screw that fell into a motor. In the end i ended up pulling both heads off to be on the safe side but its a great tool. Its one of those things you may not use very ofte, but when you do need it, its a life saver.