I installed this on
Volkswagen Jetta

Review
I bought this just for the fun of it, but I found it quite a useful device to have. Prior to getting this, I had quite jerky gearshifts, and having a turbocharged engine, I always have misfires when shifting gears. Upon having this installed, I am 'notified' on when to gearshift, and upon following this gauge, I now shift smoothly, with very little jerk, and the sound that I get from my engine upon gearshifting is just awesome. I would recommend this who would love to have smoother rides all the way!

What I like
Provides more comfort and smoothness in driving.

What I do not like
Some may find it not a need.