I am looking to upgrade my APR-chipped A6 2.7T with some wider wheels. I have it lowered via H&R Sports (~1.5").

For the past few years, I have enjoyed AT Italia Spyders (from TireRack), 18x8.5 with a 35mm offset, 235x40s. Looks nice, but I want to go wider! (Of course, I learned some hard lessons about potholes of PA and how to pay to get rims straightened.)

Some calcs I did:

As a baseline, my 18x8.5s Compared to OEM
* 0.36" further penetration into the wheel well
* 1.14" further out (wider)
* 0.4% > wheel diameter

I was wondering if Axis Penta or MRR GT-1 19x9.5s shod with 235x35 will work all the way around (I suppose I could also use 275x30)?

# With a 40mm offset
* 1.05" further penetration into the wheel well
* 1.45" further out (wider)

# With a 25mm offset
* 0.46" further penetration into the wheel well
* 2.04" further out (wider)

So, does anyone know if 19x9.5" wheels work on all four corners? (And what the best offsets/spacers should be?) And if there were any issues with rubbing?

I know that 19x8.5 is probably safe... And at least one guy was running RaderWerks MTEN-80s 18x9s ET35.

Just seeing if I could push the envelope with 19x9.5-inch wide tires all the way around.

I have also seen staggered setups offered:
* Fronts: 19x8.5 235x35x19
* Rears: 19x9.5 275x30x19

The wheel diameters are the same, so the differentials shouldn't care. Not that I'd go staggered on a Quattro.

Thanks in advance for any advice or experience you have!

(Cross-posted to the A6 Forum as well.)