Just about to buy new speakers, one salesguy said that 5x7's fit just like the 6x8's that are supposed to be in the front door.

Any opinions on that?

 

If I'm not mistaken the 5x7's will fit but you will probably need some mounting brackets. The best bet would be to goto www.crutchfield.com and act like your ordering the 5x7's and see if it says you need mounting brackets.

 

5x7 & 6x8 are interchangable sizes; they're basically the same. If you're going to mount them in a 6x8 location, then you mount them as-is... If they're going in a 5x7 location, then you simply snap off 2 little mounting tabs (1 at each end), and viola, they become 5x7's. No mounting brackets required.

 

I agree, mounting brackets won't be required.

I've also seen all 5x7/6x8's with the extra plastic or metal mounting screw holes. Its not a problem for the rear doors, but the front door speakers will need to have these extra tabs removed to fit within the "hole" then onto the mounting bracket. Typically your screw holes on on each "corner" of the speaker are the ones you'll use. The tabs on each end and possible on each side will need to be broken or filed off.

Be careful if the screw tabs are plastic, you can seperate the speaker from the metal if you twist too hard and then you've got a blown speaker before its even installed.