Last year, the roof started to act up on my wife's 2007 A4 cabrio about 2 weeks after the warranty expired, no joy with Audi who refered me back to the dealer. Car went to workshop to get checked out and 1 hour and £105 later they hit me with the news that the hydraulic pump had packed up and this will cost £1,800 to fix! I believe the pump itself was around £1,200 and the rest was labour and sundries.
After trawling the web I found my problem was very common, the hood lifting maybe 2" above the windscreen and no more, no noise from the boot where the pump is. Sometimes the hood would open fine, but then will not close, it would not go any further than opening the cover. So the motor in the pump is not turning.
Took the motor cover off and cleaned the copper moving part and made the brushes move and all was good, great! Had to do it again after a few operations, then again and again. I got on to the dealer parts and asked them if I can buy a motor without the pump and they said it was not possible. They are available to the trade apparently at around the £200 mark.
By now Wife is not speaking to me and started to look again on internet for ideas, she found Mervin on eBay (username is Autoelectron) and we got in touch and decided to have a drive up to see him in Yorkshire, its a 200 mile drive for us, but the temptation is that he promised a lasting solution for £95.00 and give a years warranty on the motor. He checked the computer and changed the motor and tested the roof several times. I think its faster too!! We have used it probably 50 times since repair, no issues. So, I could have saved all the messing about in the first place and got it fixed for less than Audi charged me for their so-called diagnosis, its a no brainer.
I have written to Audi to seek their comments on the roof issue as its a very common fault, Mervin said he had recondioned just over 250 last year and is doing 8 a week this year.
Iain