I am also firm believer of accepting the Chumras other people have, whether I want to keep them myself or not, and whether they are socially accepted in my circles or not. However, it is sometimes difficult to see the logic in certain chumras.
DaasYochid – You are definitely right. Whether or not this is the Belz reason for the ban, the R Vosner zt”l clearly writes against women driving out of tznius concerns.
But the OP has some interesting points, and certainly isn’t the first to voice these questions. What about women driving is less tznius than a women in the passenger seat?