oh I don't live in brazil anymore I live in PA

Having owned an Audi and a BMW...both handle the snow. However, you should think about parts and such. I'd recommend going with the BMW.

Rear drive is better under any conditions. The transfer of weight to the rear on accelleration is why it's simply better - peiod. Turning is a child of tires and suspension not which wheels are driving the vehicle. So too stopping.

I drive a bmmr have for years and years before that I drove benzes. I used to live in northern Maine and drove to Boston about three times a month. I could put down 90 MPH plus constant speed north of portland even in 4" of fresh powder. In the portland and south everything was slush so nothing would help but caution.

The trick to snow driving is simple. Put a like three ot four bags of sand in the trunk and learn to drive slower more cautiously and allow more room between you and other vehicles. The weight of the sand will cause the rear of the car to naturally drag behind and encourage traction. Tires for winter: Bridgestone makes a noce hydrophillic tire. It's no good for high speed or cornering but hey it's a bridgestone so you don't expect much. anyway it's a fine snow tire. I just run Michelins all year long.

Four wheel and friont drive are no more helpful than bags of sand. In fact they are worse. People think they can do more but they can not. The laws of physics determine wherher you can hold that corner or stop in some distance not which tires will turn under power.

4 and all wheel drive vehicles get going better than 2 wheel rear drive but a Positrack rear will do almost as well as 4 wheel drive. The two things no drive train geomerty will change are Stopping Distance and Centripital Force. If you are going to fast on a curve nothing will help. If you are going too fast you can't stop one whit faster with all wheel, 4 wheel, or front wheel.

Firstly... I've driven a couple Audi A8L's (a '00 and an '05), and I find them to be clausterphobic inside- lots of legroom, but very little greenhouse space. I've been in A4's and felt the same thing- very very small and crowded inside, hard to see out the back. The handling also wasn't up to either BMW or Mercedes standards, and the ride felt... soft. They are, however, pretty solid cars, and generally safe.

Audi's also tend to be very troublesome at about 100k miles or so, especially if they're not well-maintained. The '00 A8L I drove just had the tie rods done... at only 60k miles! The mechanic that services my mom's Saab says he won't touch Audi's (we were thinking of buying one at one point) due to how complex they are to diagnose and fix. Friend of my mom's had a 1979 Audi 100, and it would often refuse to start. 3 different mechanics could not figure out what was wrong, and she ended up getting rid of the car even though it only had something like 50k miles on it. 90's A4's had problems with the engine (1.8T models), front suspension (same as the Jetta- very flimsy quality), and automatic transmission. That being said, if you're both a) lucky, and b) maintain it well, an Audi CAN last for as long as a BMW or Mercedes.

That being said... older BMW's are hit and miss too. Make sure you get one that's well-maintained, as if not you'll be running into a lot of problems. My old '87 325e was a disaster- every couple hundred miles it'd be a $500 repair, and every couple thousand it'd be $1000+. Both Audi and BMW are known for electrical problems. Take a look at the '92 318i or 325i, with as few features as possible. Good starter cars, exceptionally well-built, and generally in the $2-4k range. Get a set of snow tyres and put sandbags in the trunk, use the lower gears, drive slowly... and you won't have trouble in the snow.

I had a 1999 Audi A6 and a liked it a lot more than my current car (a 2005 BMW X3) which I'm leasing, thank god. Which car you'll be happier with depends on what you're looking for. I like my cars to be more comfortable(A6), and I take that over performance and handling (X3). If you're priorities are different, you may be happier with a BMW. As far as driving in the snow, a set of snow tires will address and overcompensate for rear-wheel drive. (I know this b/c a friend of mine has an M3 and, in the winter with snow tires, he passes SUV's.)