Quick report : Mazda3 in the snow.........
 

So my Mazda3 was less than 2000 miles old and we took a long trip for skiing; I was prepared with Z-chains and early in the morning the CHP was stopping everyone, checking for either 4 wheel+snow tires or chains.

A few miles past the chain check we hit ice and snow and put on the chains.

The chains are great !! You clearly have better braking and control than a regular SUV with AWD. Its a bit of a pain in that you are limited to 30 mph.

Let me know if you need any more info on snow chains on the M3 or have experience of snow driving. I left the 'DSC' activated, but was a touch unsure if this was for the best.

I just bought my 07 3, and here in Illinois I got some quick experience with it in snow. It really sucks. But, I realize that is because of the 17" wheels and low profile tires. If I really wanted to make sure it went well in snow I would get some 16" wheels and Blizzaks.

I used the Shur Grip Z-Chains on my 2000 Crown Vic. It gives you the same ride quality and NVH as a M2 Bradley Fighting Vehicle. I would not recommend using them for prolonged trips. They work great for emergencies though.

I just mounted 205/55 16" rims with Dunlap Winter Sport tires on my 2009 Mazda 3 HB. We are expecting snow here tomorrow, so I hope to have some impressions to report.

Consider studded snows (if they'll let you)
 

We have a 2007 M3 HB. Living in the northeast, I feel that 4 studded snows are the way to go for the winter season (They're permitted in NY state). I bought a set of studded Winterforce snows last season from Tire Rack. They did fine in the snow that we get here. I also have a Saab 9-5 wagon equipped with similar snows. I think, because of its extra weight, it does much better in the snow than the M3. This season, I added 100 pounds of sand over the rear wheels, which seems to help the car cope somewhat better with snowy conditions.

YMMV
Bob