Control Arms Already?
 

I have a 2005 A6, 85K 90% of them highway, since I've had it. (6 years/ 60 K miles) repair shop wants $1900 to replace both upper and lower control arms. Does this sound reasonable?
Do the control arms go this soon?

NO!!!!!! You can get the entire front end kit on EBAY Upper and Lower control arms, lower tie rods, tie rod links, and sway bar links for $ 650. If you pay cash you should be able to find a competent mechanic to do it for $500-700. I'm guessing your quote was from a dealership although 1900 is pretty low for them to be honest. I was quoted at 2800 believe it or not. I almost swallowed my phone I laughed so hard. I'm having my done for 600 labor. I bought the kit so the grand total will be 1250. Of course this is cash under the table. ;)

Oh I forgot, 85k miles seems a little low especially since you are driving 90% hwy. Mine has 145k miles. Noise started around 135k miles and I'm finally doing it. Usually the noise you here comes from the sway bar links, so this may be all you need, but never hurts to replace everything at once. Good luck. If you have any trouble finding the kit shoot me a message.

When you buy it off of ebay make sure it is the exact match!

I had bought one from ebay for like 300 bucks and almost kilt my self last night when one of the control arms came off. I think the kit was designed for a6 and i had an a4, but i notcied it after the fact and decided to go for it anyways (big mistake).

Mechanic charged me about 1050 (cash:)). Had my control arms, shocks and one axle replaced.