Not sure spacers are the way to go. I have heard of using Coilovers but on the RS4 not sure it will work because the DRC is designed to work at a certain stance. If you raise or lower the car the valving will not be working as designed and it could cause more wear, but I am not an expert on that. .

I would say it is a good approach and I run all seasons for my summer tires - they get better life and are much quieter - plus here in Colorado we can get snow in the summer too.

But I have to warn you that to count on the car in a snow storm in the winter with all seasons can be risky. If you have alternate transportation when the weather is horrid then go for it.

But with the wide tires we have - I can't say for sure that A/S tires will get you through if you must drive. I tried all seasons on my Q5 the first winter and it was very scary in the blizzards and black ice that I encountered. I discovered too late in the season to put new rims and snow tires on that winter but went down from 20" to 19's and snow tires -much better