"Insist on Clean Windows: It's Our Job." So read the T-shirts worn by the handful of high school-aged boys and girls working the back end of the Waterway car wash, located within a BP filling station off of Watson Road, near River Des Peres. But "insist" is such a strong verb — maybe you're too polite too insist on much of anything, lest you rankle nerves or rustle feathers. Here's the great thing about Waterway (at the Shrewsbury location or any of the seven other centers around town): You'll never have to insist on clean windows. The towel-ready crew buffs your windows to a shine every time, whether you opt for the $5 exterior wash ($5 if you purchase gas, that is) or buck up for the full wash-and-wax detailing jobs. Once your car exits the automated washing tunnel, those fresh-faced, unfailingly polite youngsters put the human touch on your car wash. And the human touch is what separates good car washes from great ones, provided that you are not the human providing the touch. Luckily, Waterway has a small army of towel jockeys ready to do it for you.