What size do I need to remove those bolts holding on the rear seats? Are these #50? Thanks

2000 Contour Black V6 SE ATX Moon traction control ABS
still all stock but not much longer:-)
Eclipse 55430 HU
Eclipse DSP 2301
a/d/s P850 amplifier
a/d/s 345is components front
a/d/s A4im rear deck
shopping for a sub.

1995 Contour Midnight Blue SE V6 ATX, 160,000 Miles and still strong as ever, Leather(soon to be switched to my 2000),traction control.

" so roll down the windows and let the wind blow back your hair.
The night's busted open, these two lanes will take us anywhere..."