This was taken last year after a forty mile drive on a day when all the media were saying 'don't go out'. 500 is fine, handles the conditions as well as anyone has a right to expect from a small family car.
Modifications will, I've no doubt, improve the car's ability to cope with snow but only if combined with special tyres, tyre pressures, driving skills and balanced load, all good on a track but diffficult to achieve in real life. Most folks survive perfectly well without!
The driving advice given above is sound, mostly concentrate on the 'take it easy' and anticipate so you can ease off the speed rather than excessive braking.
If you get a chance skid pans are instructive and fun or if you venture out, perhaps with a trusted friend, and you happen to find a wide open, empty, snow covered car park then try some slow speed turns and braking in there to get a feel for what happens.
Don't scare yourself but gain experience and thus confidence - 500 is a good friend!
