Anyone know where I might could find part # hja2056aa? It's the small plastic cover for home link switch

 

Your best bet is someone parting out an XK8 to get an exact match. You can get the right color, too, that way.

I am 100% positive there are other Homelink switch plates that will physically work (since the button spacing is the same on all oval button units and the only thing that really changes is the mounting pin length and style - pin spacing is the same), but I don't know what those other vehicles are.

Most later Homelink cars that use this style plate were visor mount, and the visor mounts have slightly shorter mounting pins on the cover plates than Jag's.... nothing hot glue can't fix.