If I were to bolt/screw the docking sled to the cage in the dash would there be any reason why I couldn't cut a few mm from the front of the whole sled so the metal lip wouldn't show and so the empeg will mount completely flush against the dash?

Well, I guess the only problem may be the latch that locks/snaps the empeg into the sled itself.

Since I don't have it handy, how far is it from the sled "lip" to the front edge of the anchor slot?

Thanks

John M