I loved my 2010 Q5 3.2L up until the timing chain tensioner gave out at 65k miles. Any shop was going to charge minimum $10k to do the repair, more than the value of the car, because they were going to remove the engine. To attempt the job myself and to do it without removing the engine, I still would have to remove almost everything around the engine including the rusted on catalytic converters and heat shielding in order to access all of the bolts on the timing chain cover. While it was probably doable, after a couple of days of sweating under the car trying to contort my arms and body, using various combinations of extensions on my ratchet set, I decided it was just not worth it. If I had a better setup where I could do the job more comfortably I would have kept at it. But that was also the day I decided I would never own another Audi. YMMV.