I have a set of these on my convertible and they actually work pretty well. Here are three things to keep in mind if you are thinking of using them:
1. Be prepared to remove your parking brake peddle since there won't be enough room between the speaker and the peddle. The panel is molded to fit a speaker totally in the panel which causes it to kick out more than a normal panel would. Typically there is a cutout in the car for the magnet to set into and these panels are designed for retrofits. This is pretty easy to remove and put back later on however if you are using the brake, you won't have it any longer. Make sure your speakers have a slim enough profile that they do not exceed this space.
2. My speaker grilles pop off easily because the speaker comes into the peddle area and they get kicked easily. Not a big deal, just irritating.
3. Your fresh air vents will no longer operate since you are now blocking off the outlet with a speaker. Make sure they are closed or you could possibly have other issues later on.
The sacrifice is worth the return and it's nice to know that I have everything to put it all back to original later on.
Just my two cents..
Chris