Recently bought the A8L SE FSI CVT 2007 from a small car trader on auto trader about two weeks ago and as luck would it..

Mileage about: 50,000
Engine size: 3.2l petrol

First weekend drove 300 miles no problem

Second weekend drove 280 miles (motorway)...oh boy..PROBLEMSS!!

Have no idea what is causing them so any tips/helps most appreciated. Problems that occurred:

1 - Cruise control started switching itself off automatically and wouldn't come back on. No warning lights

2 - When accelerating (not aggressive), the car randomly de-accelrating as if it is engine braking or I am pressing down on the clutch (if it was a manual that's how it felt)..so I had to quickly let my foot off the gas then try again slowly..only for it to accelerate a little and then start going down in speed. The strange thing was that the more I pressed the gas (as the speed was going down) then the quicker it went down! Still no warning lights. I have had a turbo fail on me before on my BMW E60 and this did not feel like that because that was loss of power but the car still accelerates..this was the opposite

3 - Warning light for parking brake comes on..lights at the back start to turn on and off randomly and also start flickering!

4 - Warning light comes on for ERS

Pull up on the hard shoulder...switch it off..rest for a few minutes and drive off.. absolutely no problems for a few minutes then all started happening again!!

I am lost as to what could be causing so many problems...any guidance greatly appreciated.

 

#2 sounds like the secondary (LHS) fuel pump is bad.

Best thing to do would be to get a VCDS and scan for DTCs. Ross-Tech Store

From there you can decide between DIY repairs, or booking into a main dealer or indy.
If you decide to do the work yourself the Bentley is invaluable.
Find My Car *-* Bentley Publishers - Repair Manuals and Automotive Books

I wasn't aware they ever made an A8 with a CVT or a 3.2.
Are you in the UK ?

Also will want to have a look at the maintenance schedule Audi Service > Audi of America

 

Yes in the UK..interesting you say its the secondary fuel pump as I have some people say it may be the parking brake sensor which may be cutting power to the engine as it thinks I have applied brakes..

vcds sounds like a sensible suggestion just need to find someone local who has it...

I will be going back to the small dealer to get him to repair it or take it back as obviously don't want to end up paying for repairs for a car which I have only had for 2 weeks!!

 

It's very possible it's the brake sensor based on the other symptoms....
Just thinking out loud on the fuel pump

If you can get a scan ahead of time it may be more leverage for you with the dealer.

These are complex vehicle, and sometimes can cost quite a bit to repair.
I bought a 2005 about 3 years ago and put about $8,000 US into it including new tyres.
Out of the gate I had to do the 75,000 mile maintenance, which on an 05 includes a timing belt, for $2,500.

That said, I'd do it all over again and if you can get the issues worked out or find another one, you will fall in love with the A8.
On my second A8 and we have an A6 in the family too.
My advice to anyone is don't buy without a scan ahead of time or a very good return policy.

Hope you get it figured out soon, and hopefully will just be minor things!