dubbing

Afternoon all, Firstly apologies if this has been covered before. I have been car enthusiast for many years, owning a range of VW's & BMW's. But now in a position where I feel a 4x4 would be best suited. I have taken a liking to the Audi Q7 and find myself keep coming back to them. I have a budget of £20,000 but would ideally like to spend less than this, if possible. It'd have to be something special for me to go over the budget, but wouldn't rule it out, if the right car came up. I am new to the Audi world, but would like it to have at least some S-Line spec. What are the running costs of owning a vehicle like this? What are repair/maintenance costs like? What are the common problems? I have seen some 2010 plate models onwards, and then seem to have a decent spec. Thanks in advance!