Lately after washing my car, I've noticed the front passenger wheel has alot of residual grime still, and all others are spotless. There's more built-up grime inside the wheel, too. I haven't jacked it up and checked the CV boot yet, but could that be causing it?
What other symptoms would I notice in addition to that?
Whatever is getting on the wheel is actually staining it and requiring a seperate wheel cleaner and scrubbing to clean it AFTER going through the car wash.
What else could be leaking/causing this?
Thanks~
Jeremy
By the way, it's a 2004 A6 2.7T quattro.
I bought the car with 56K on the clock and don't have any service records of the CV boots ever having been replaced yet.

 

When CV boots crack they start to throw grease around into the wheel well and onto the wheels. There is no additional noise, until later when the CV joint dries out and starts to make "clunk" sounds usually when turning steering wheel hard at low speeds.
Get it up on the hoist, it's cheaper to replace the boot now, than the whole CV joint/axle later. Check all 4 front boots, they're all as old/ as many miles as the leaking one.

 

most likely, follow the advice below and get them looked at/chnaged ASAP before it becomes a more costly repair. A crakced CV boot does throw out alot of grease out in the inside of the wheels

 

The outer CV boots are the ones that fail the most. The inner boots don't have to flex and stretch nearly as much as the outers do when you're turning the wheels. Best to do both outers at the same time. If one is bad the other isn't far behind. Boot kits are only $15 each from here: http://www.purems.com/products/product.php/II=1453. I put 2 of these on last summer.

 

Did you check the brake caliper? Sometimes it leaks as well.