i WAS wondering if my 1999 sebring convertable jxi had a factory amp and if so where whould it be?

In my 1996 jxi, it was under the passenger seat.

I agree with Billy Bob, it was a shallow metal enclosure with heat sinks, fastened to the floor beneath the front passenger seat in my 2000 jXI

Yuppers as above , under the front passenger seat in my 99 JXi.

we have a 1999 chrysler sebring convertible jx that we cannot find the factory amp its not under the front seat??

Then you don't have a factory amplifier. Under the front passenger seat is the install location. Someone may have put a newer stereo unit in with more power. I put one from a 2004 in mine (with a little mounting modification) . The newer unit had much more power then the 99 did. Someone may have added an amp as well. I would dig around in the trunk. !~Good Luck~

The amp was optional. So, although you have the Infinity Sound System, your car was not ordered with the amp option. Kinda like 4th gen F-bodies. They all have the hook up for factory fog lights in the wiring, just no sockets or bulbs or switch.