Mustang left and right lower control arm rotten?

I have a 1994 Ford Mustang; have owned it since it was new. I was recently told that my left and right lower control arm mounts are rotten. I have tried doing research on this and can't find a straight answer. What will happen if and when they rot through? I would take a picture but I do not know where to take a picture. I can only seem to find information regarding the lower control arms themselves, not the mount. Luckily this is not my main car and does not get many miles put on it.

My next question would be has anyone else heard of this happening, and what is the approximate cost to get it fixed (I know it depends on the car and many, many other factors).

Just one other thing, the car is not doing anything out of the ordinary as of right now, the steering is fine and it drives very smoothly. I was told that mechanically the car is in good shape (transmission, engine etc.).

If and when they or even one rots through most likely lose control of your vehicle unless it breaks sitting still.

The control arm mount might be a dealer item, call a Ford dealership and ask or best would be to take it to an autobodyshop for a free estimate, they may be able to fabricate them if need be, besides that would be an autobodyshop job to weld in new mounts and while you are there check around under the rear bumper, I worked on one thinking there was a minor rust whole in the rear quarter panel and went to take off the bumper the car was rusted so bad it would cost more to fix it right then the car is worth but if you open the back hatch or trunk pull up the carpet and look behind the wheel wells for rust holes and plug them up with sheet metal, sheet metal screws and black jack so the exhaust fumes can't get in at least.