On the camera thing, the fibre optic cameras are getting quite cheap these days. Back when I was working we had a couple for inspecting tubes on heat exchangers, etc, and they were very expensive (we're talking thousands of pounds) but they've come down a lot in recent years. I've seen them in Costco over here with a fibre optic lead and a hand held monitor so I'm sure they're very common over your side of the pond.
A couple of months ago I bought one from Ebay for the magnificent sum of £12, just for something to mess around with. It's only a lead which plugs into your laptop USB port and gets power from there, but I was surprised to find it actually works. The resolution and focus depth aren't great but on the plus side I did manage to view inside the clutch bellhousing on my car, pick out the release bearing/input shaft/etc.
It certainly beats a mirror on a stick and you'd easily send it down a chassis cross member and pick up if there's any heavy rust or holes.
The trick is understanding what you see because the view on screen is much closer than you're used to seeing and so small objects can look scarily large. The software with mine had a scale for identifying how big objects really are and that worked ok, plus of course you can capture images or video as you do the inspection.
Brian