The best thing you can do is have any oil leaks on your vehicle cleaned well, and then add dye to your engine oil. You'll then need to drive the vehicle a bit to have the oil leak out where it is leaking again. Following this, a black UV light can be used to shine on the oil leak areas to see where the leak is originating from.
RepairPal Certified shops can diagnose and repair your 2007 Audi Q7. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.