I'm not a car expert by any stretch of the imagination, so I'll ask those of you who are. Do you think it would be possible to mount even smaller rims on the Model S, like 18 or even 17"? I'm in a rural area that receives a lot of snow in winter, and lots of bumpy roads. I've heard the pro's and con's about 19" vs 21" - would the differences be even more pronounced with smaller rims? Would there be major negatives, or is it more a personal preference in terms of looks? Please enlighten me.