245/45/R18 seems to be the perfect size for the upgrade on the A8, since compared to the stock 225/55/R17 size, the difference is -.27%. Perfect.

Where can I find 4 wheels/tires of this size all for a max of 2 grand? Don't care if tires/wheels are slightly used.

I got a set of brand new wheels and tires off of ebay for $1650 plus shipping. The wheels are 18" X 8" ET 32 sold by A!Avantgarde but manufactured by BBS in Germany. The tires are 235-50-ZR18 Yokahama AVS sport, and they are really high performance- I love them. (A lirtle noisy, but I'm willing to accept that for the performance level.) The tires sell on the tirerack for $250 each, and the wheels (if you can find them) sell for around $475 in this size. These were already mounted and balanced, so I didn't have to let the local tire monkeys touch them (yet). The source was an Audi dealer in Florida- they had these wheels/tires mounted on an A8 on their showroom floor, and whoever bought the car didn't want them. They sat in the warehouse for a year and then the dealer ebayed them. The total milage on them was about 300 feet- from the service bay to the showroom floor and back to the service bay! Deals like this show up on ebay every now and then, but be sure that whatever you get fits the A8 properly! See my signature photo, or search the forum for the photos I posted when I first got them (search for "new wheels"). Good luck in your search!

Thanks for the info, I'll be looking around. Ultimately though, I keep saying to myself I should get the Michelin Pilot Sport A/S tires because they are truly the best all-seasons-all-reasons tires. See the thing is, even though the stock Goodyears I have now are touring A/S tires, they totally s**k. So with the much higher-performing Michelins, those will do EVEN BETTER in the snow than the Goodyears.

I dunno, I'll do lots of research of course before deciding.

I use my 16" stock wheels with Dunlop Wintersport M2 snow tires for the winter, which allows me to run a dedicated ultra-high performance tire on my 18" wheels in the summer. The smaller diameter wheel is actually better for winter use, and if you have the storage area available I would consider having two sets of wheels/tires. The best of both worlds!!

If you find an 18x8.5 rim consider 255/55/18 tires as there are more choices in this size. They are a little taller by .3" and actually fill out the wheel well. I have BBS CH's with this size and am very happy with them (Thanks to the good advice of "RYOUNG" on this forum. Many thaks Randy.)

It doesn't snow enough in Boston, dedicated snow tires not worth it.

I'll be getting the Pilot Sport A/S tires then.