I also think it's edmunds.com or cars.com. I know I've seen it a hundred times, but forget where.

On kbb.com, I pulled up the used car pricing for my car, then clicked "reviews" on the left sidebar. That brought up an old professional review with the MSRP listed, but not with the options (and bodystyle, even).

A forum for the make/model of the car may have the MSRP in some database. I know I've seen them somewhere.....