IMNSHO, the driver's side one only get in the way when you put too tall of a bottle in it - i.e. 20oz water bottle or the like (soda, etc.). Otherwise they are great - no spillage, etc. Mostly though, when driving by myself, I just put my drink in the passenger side holder. They're usually back a little further - just right up to the seat.
Yeah, yeah, I know.... I need to clean my floor mats - maybe this weekend
then again....maybe not
