I have fitted these to my Mazda and they are a fantastic product, sounds great in the car. Much louder and clearer than the originals.
I also did a bit of head scratching when trying to screw these in place, after reading an earlier review saying to twist them so that the "jvc" logo was pointing towards the front of the car it was then relatively easy. finished the fitting with the clips from the kit and the origional screws.
Also, dont know if this makes a difference but I brought the red and white wire into the + connection marked on the speakers and the green and red wire into the - connector, works fine like this.
Delivery would have been great if the courier driver had rang the bell (4 people in the house and i got a "sorry we missed you" ticket).
So apart from having to pick them up and a few initial fixing issues these are fantastic.