Well darn you Blacklane. I tried a 12 oz soda can and a 16 oz styro cup that I use for my coffee. Neither fits well, at all. Leaves them sitting way to high and wedged in. I do have an automatics transmission (and cruise control, Yay!) so shifting isn't a problem. I think I'm going to remove the bottom up to and including the step in each holder. That should let a cup sit much deeper and be more stable. Will report in later.