I have yet to read the documentation. At first glance, it looks...

I have yet to read the documentation. At first glance, it looks to be an attractive sector in which to invest.

But:

I agree re courts. Clever solicitors and barristers who specialise in such alleged offences will find all sorts of holes in the technology, and create precedents that magistrates and judges will be inclined to follow. Fines or other sanctions can always be appealed (provided one obeys time limits).

These mobile trailer units have security features. However, surely they're sitting ducks for vandals and other criminals?

These individuals will rock up fully covered, including wearing hoodies, sunglasses, hats and even masks, plus full body clothing, and damage these enforcement trailers. They're innovative, so if their contempt for road offence detection equipment is strong enough, perhaps they'll vandalise these units with drones. I don't condone their behavious but given conservatively set speed limits, there's a lot of anger among motorists re getting fined.

Many drivers regard it as a God-given right to access their smartphone while driving, so there's resentment if they're pinged.

Re mobile speed camera operators, some were attacked (or their cars were) in Victoria in the past couple of years.

The risk of being caught and arrested by police is little deterrent.

Eventually RDF was taken over by some outfit called Verra but RDF had a rather 'interesting' history if I recall.