I think polarized sunglasses are suitable for driving because these sunglasses can reduce the glare from the water, snow and glass.They can help people see more clearly and prevent from potential hazards,so the polarized sunglasses are highly used for driving,fishing and sports.The polarized sunglasses are more expensive than the regular sunglasses,but you do need these sunglasses for driving. You can get them at the mall which they have discount area.You can also buy them online because they are cheaper than the real store.
If you just want to wear for driving, i recommend you to buy polarized sunglasses. Compared common sunglasses that shield your eyes from UV rays and reduce strong sunlight, polarized sunglasses can also filter glares from water surface or other smooth surface. SO, they can provide your more comfortable vision when you drive. Besides, if you often drive in night, you can also prepare a pair of night vision sunglasses which are special made for wearing in night to drivers. Anyway, you can find polarized sunglasses at almost every eyeglasses shop who sold sunglasses. Just go ahead. Good luck.