It was the Scorpion I was launching / recovering.
The Avon i'm happy to move with the Audi. Used to use a 205GTI to tow a 4m searider a few years ago!
Interesting what you say about the Volvo 4WD system prone to failing. Have read around the forums a bit and some of the American sites mention auto gearbox problems due to the oil not being changed but 4WD failures seem to be almost exclusively XC90.
I think i'll leave the Volvo at its 163hp - its not worth the money to make a slow car slightly less slow - and if there are any drive shaft weaknesses I don't want to tempt fate!
If I want to go fast i've got the Audi - and that IS remapped
Need to get the trailer serviced next. Was happy with iffy brakes when using the Discovery but the Volvo is a little lighter.