I purchased a wireles unit off ebay from Citrus Motors. Just a glue on unit as there isn't a clean place to mount it on the door like you had on your explorer, so I mounted it on the rear liftgate, upper left side below the escape logo. I have had more complements that you can imagine!
Since you only use when you lock the keys etc---it's out of the way until needed. Of course being Polish I had to use it the forst day...... | 
