After additional web research, I am beginning to suspect that it's actually a Brighton model, not an L. The dealer is double-checking the VIN number to be sure, (he assumed it was an L because it has power windows) but everything I've found says that the L model started putting in rear headrests in 2000, and coincidentally the Brighton added power windows that year also. He's supposed to call me back - we'll see..... Unfortunately, the headrests don't seem to be available for the Brighton.
I love the internet!!!
Diane