At 65mph in fifth I feel like I should have one more gear reduction available. The engine just seems to sound as if I should still shift one more time. However, I agree, the use of space in the 500's engine compartment is extraordinary as is. Adding an additional gear - even if that gear were made to the second and third gear ratios with both becoming a taller gear ratio followed by a slight redesign of the 4 and 5 gear ratios - would not fit into the present configuration of the 500. If the sixth gear ratio could be fitted to the transmission while, say, giving up no more than an extra inch of leg room on the passenger side, that would IMO be worth it.