I installed the Crime Guard 533i4 that I bought for my 6th gen LX from Crutchfield. I bought 3 harnesses from Crutchfield as well. The alarm kicks major arse, and took all of 2 hours to install myself. SImply unplug the factory harnesses and plug the new ones in. I highly recommend this system. The best thing is that if i ever want to sell my car and keep the alarm, I can merely unplug the harnesses and buy new ones to fit whatever car I would be getting afterwards.