Some of the square ones work, the peanut ones work, but the rectangular ones don't.
two outside ones work (FCCID of CWTWB1U313)(they are from my 2000 Grand Marquis)
the peanut shaped one works (it is what came with the car)
the taller more rectangular one doesn't (it is from my 97 Cougar)
I have tried a few other square shaped ones, FCCID CWTWB1U331 and it didn't work.
I switched from the peanut shaped one for a couple of reasons:
it was broken, and most of them are broken, and the break easy
the range was horrible, 10 feet
no cheap easily available replacement cases or silicone covers
For a couple bucks a piece, and a long wait from Hong Kong, I got some replacement cases, I also got some silicone covers. There are sellers on eBay with cases but more than I wanted to spend.
In reality I want to install an aftermarket remote entry, remote start, alarm. Even my 89 Cougar has remote start.