HiTEC

I've pinpointed a serious squeak in my car to the rear speakers. If I have somebody put pressure on the speaker grill while driving it stops. I've tried to get the dealer to fix, but I waste several hours of my time that day to only have them say they don't hear any squeaks. So as I originally thought I'll be fixing myself.

Do I have to remove the rear seat to get at the speaker access? It looks like in the pictures I saw that was the case. Any tips would be helpful.

Thanks!