vtraudt

The front passenger side speaker scratches, and the front driver side speaker does not work at all. I have been looking for used/cheap Audi speakers, but none found.
I want to fix it now. Does anyone have used speakers that fit?
If not, what aftermarket ones (size) do I need to get?

How can I tell if the upper (tweeters) work or also need to be replaced?

Reggie

I think the Crutchfield website will tell you what speakers sizes are used.

OnoOlaMas

I'm pretty sure it depends on the model/options your car has on it but from what I remember mine had 3.5 components. Its pretty easy to take the door panel off to take a look. I think you can easily mount the 5" components without modification and the tweeter is a standard 1". Either way go with a component set with a proper cross-over.

As far as buying the speakers... I'm a bit of an audiophile... so I would always recommend spending a day of shopping at the local car audio shops (not future shop or what-ever) and actually have a listen to what you're going to buy. They often have the same if not better pricing.

vtraudt

Crutchfield says 4" units work. But aftermarket speaker have 4 mounting holes, Audi (non Bose) has 3. This requires to make a custom adapter or else.

Audiophile: same here (not so much in a car, but at home).
Huge difference in 'hearing' speakers (vs. looking at a name plate or price tag). That is one reason why I actually like the old Audi Bose (very low distortion, good sound at any level)

I should have a few Magnat (was a decent car and audi speaker years back) around, will check their size. Once I have parts on hand, I will dig into the doors.

I always hesitate to take the door internals off. Chances are some plastic pins/fasteners break, and the gooey glue and plastic will never go back in its place!