Today I went to an outdoor spot that has a long, 3/4 mile uphill drive that is complete, continous sheet of smooth glare ice for the last 1 week due to plowing & weather patterns (no sand or slat is applied all winter... melt/refreeze = glare ice). There is a locked gate at the bottom on moderately steep incline that you have to stop, unlock, drive through, relock, and then proceed uphill. the ice is so slippery that it is difficult to stand on, and my ABS went off slowing to a stop from moderate speed, lightly braking, going UPHILL. The incline is steep enough that without ASR one wheel would simply spin and you would actually go BACKWARD.
I was able to inch forward with the help of ASR through the gate, stop, and again restart for a second time on the moderate smooth glare ice incline, gain momentum going uphill, and generate and keep enough momentum to navigate the curves and MUCH steeper inclines further up the drive. I gambled that the car would do it... it was challenging in my Tacoma with 4wd earlier this week (both axles spinning from a dead stop feathering the clutch, slow pregress) and conditions were even more slippery today in the VW based on walking feel. But, the car did it with FLYING colors, VERY impressed.
Unstudded Michelin X-Ice i2 winter tires, FYI.