Hi all. I have a 2001 Bonneville and I'm in the process of putting a system in my car. I found 2 different sites stating that the front door speakers are 6.5 inch and 6.75 inch. Anyone know what size is correct?

just take out the old ones and you'll know
sorry to be blunt but thats my best solution

Have you checked Crutchfield yet? They are usually pretty good about what fits and what doesn't fit....

http://www.crutchfield.com

crutchfield is probably the best website to get all that information, although their prices are not as good

I've got a 2000 with the Bose, sorry HAD the Bose, 6.5" will fit. You'll have to do something about a grill though, because 6.5" is all you've got in the openings. Unfortunately the easy route (Crutchfield ) hasn't been measured. I actually measured the plastic bits and height on the back for direct replacement. I'll try digging these numbers up for you. And if I remember right, their were some bizarre numbers for a direct fit.

I ordered a pair of 6.5" today but what do you mean I have to do something about the grill? I just cant install the new speaker and put the new grill on or use the old one?

That would be great if you could get those numbers for me. I swear, I dont know what I'd do without this forum!

Usually the grilles are a bit bigger than the outside diameter of the speaker. And 6.5" is all I had to use. You may be able to use the original grill depending upon if you mount them on the front or the back. I'll get the measurements for you when I get home from work tonight. When I said 6.5" inches would fit, I meant on the front side. I'm not 100% sure on the back, hence I'll get those measurements for you.

Sorry about the delay. My job tends to ruin any hope of a life.
The mounting holes are 6.25" on center. For depth, you can get away with ~2.5"-2.75" depending on the size of the speaker magnet. A 3.5" magnet will give you the 2.5" depth, anything bigger may have issues much deeper than that (unless you want to look into cutting sheetmetal). Depending on the excursion of the driver (Xmax) you could also have problems with the speaker bouncing off the panel using the factory mounting. I think thats it.
I just spent 15 hours on planes so I'm pretty confident I forgot something. What kind of drivers did you order?