I've been an audi fan for nearly 15 years. Both Audi and VW's are very nice cars in my book, but not for the faint of heart. In my experience the failure rates are 3-4X's higher with them compared to the Honda/Acura's I've owned. And the parts prices are often very high as well. That said, a well-sorted 5 year old German car (or Mexican as the case may be) feels a lot more solid to me than a brand new japanese car off the line. But, it takes a special kind of person (patience and money) to keep that german car "well-sorted"!
I put up with them, and they certainly test my patience, but when my family, who love the reliability of Toyota's and Honda's, ask about a VW and Audi, I steer them away. Even my wife has no tolerance for it. She rolls her eyes every time I tell her I found another issue with the Audi. ("why don't you buy a new car?")
That said, here are my thoughts.
If it has the 1.8T engine, in the A4's, those engines threw timing belts as early as 60K, even though Audi recommended 90K. The tensioners would **** out. If it's a 1.8T, I would do the TB now and every 60K thereafter. Water pump and thermostat as well while you're in there.
Skip the triple squares until you need them. CV job or anything that requires removing an axle will require them. For now just get that metric 3/8" allen head socket set. You will use those everywhere.
Brake tool - yes. 13mm ratcheting wrench and a
super thin 15 mm wrench to counterhold the brake slide. Cycle shops usually sell that later, which works quite well. Vag.com - yes. Not just useful for electrical stuff. These cars have sensors everywhere, so being able to pull the codes, read the measuring blocks, etc. is very helpful. Can't own an older Audi/VW without these imho.
Start thinking about replacing the shocks. By 75K they start to deteriorate rapidly.
If that engine has coilpacks on it, keep at least one on the shelf for emergencies. Or for $100, replace all 4 and leave the originals on the shelf for emergencies.
If you have a turbo motor on that car, do 2 oil changes at 500 mile intervals with regular dino oil. If there is sludge in the system, you'll see it start to flush out, if not, great! Then switch to the recommended weight synthetic and stay on that. You should be fine at 5K intervals.
Watch out for plastic bits in the engine bay. If you touch them, fully expect them to disintegrate in your hands. If you don't touch them, consider them suspect anyway. When the car throws a code, there is a 50% chance it's one of those plastic bits under the hood.
Replace vacuum hoses. They will likely be brittle and ready to go. If the car has a diverter valve, replace that too.
Check for coolant leaks. The reservoir cap and hoses are likely suspects, get a visual on the end tanks of the radiator (probably plastic - remember what I said about plastic bits).
Wheel bearings - throw it around some on and off ramps and listen for the tell tale sounds. If you're doing the suspension and one of the wheel bearings are bad, may as well do them together. Do the wheel bearings in pairs. Usually the other side is within a few K of going bad anyway.
That's the stuff that comes to mind. If you have a good basic collection of tools, I wouldn't go crazy buying tools until the need arises.
