its been done - i personally think it looks weird because the bumper itself comes out so much farther than the lower lip where you would attach the chin spoiler. plus the contours are different and it might be a PITA to get the shape without distorting it.
I'm going to get one on mine. I'll post pics as soon as i do. I think it looks awesome! There's a white notch i've seen at the drag strip that has one. It looks so sick!
I think it would look better on a GT or maybe a Saleen bumper, the LX has what I call the 'Ford overbite' like most other Fords from that era and then some. I seen that LRS car a million times and I never noticed that spoiler untill now.
Someone on here used a garage door seal on his GT awhile back for a chin spoiler. For what it was it looked alright, if they made a direct fit peice I'd like it more.