I installed my SU front motor mount today. The install is very easy. It took me about 40 minutes, just because I am slow and was not in a hurry. I took it for a ride and I am impressed in the difference. The motor doesn't seem to move as much when shifting and feels much more solid. I did not notice any additional vibration entering the cabin. I drive my MSP daily and did not want any ride discomfort. This was an excellent mod, especially for the price. Mazda should have done this in the beginning. As a note, the stock front mount is very flexible, and should be replaced. I also noticed that I do not get as much vibrational noise that I was getting before the install. The motor just moves to much with the stock mounts. I do not feel that I need to replace the rear mount. I only boost 7 psi and the front replacement improved things significantly without any detrimental side effects.