While I had the RS6 I did just under 19,000 miles, burnt 4,360l of V-bastard, and paid Mr Shell £5,802.01 for the priviledge. Maintenance and upgrades came to £10,000 and included:
Bilstein PSS9s
Miltek Cat-Back
Re-con intercoolers
Cam-belt
Gear box health check and new sump (old one was corroded, lucky it was caught - I'd highly recommend a gearbox service if you've not had it done already)
2x new MAFs
4x new tyres
Alternator due to failure
New engine ECU due to failure
Unti 20 Stage 1 remap of engine and gearbox
All of the above work was carried out by Unit 20, and I have to say they were a big plus point in RS6 ownership - you can't put a price on knowledgable efficient and friendly service.
I got the car with issues, and having addressed the big expensive bits (and recently had the remap done) I suppose it would have made sense to keep the car for longer and enjoy the good condition it was in, but a) I'm a bit impulsive and b) I've learned you can never tell when the next big bill is going to come your way with an RS6, so the time to change felt right.
It's been great reading all the posts on here over the years, and I'm sure I'll keep lurking around to see if Badmans has anymore irresistable bargains on offer, but for now, that's me RS-less.
Let the TVR/canoe digs commence!
