The link below allows you to compare 5, 20, 35 and 50% tint by scrolling over the numbers. I think it's pretty accurate in terms of looks.

Top of the line tint, New Jersey's finest glass tinting shop - Professional Automotive Tinting

5% is basically limo tint, if that's what you're looking for. I did 20% for rear sides and hatch, and 35% for the front sides. Best option would have been 20 all-around, but I did not want problems with the cops. FWIW, the 35 on the fronts transitions nicely to the 20 in the rears. It does not have the harsh contrast of 20% on the back with no tints on the front, like you see in some vehicles. I'll post pics later.