Are you aware that the 4.2L models don't have two backup lights? On LHD (North American market) cars, the backup light is on the right rear and a fog light (bright red) is on the left rear. That's because the driver's side is closest to the center line of the roadway, and the rear fog light shows drivers behind you the middle of the road.

It's the opposite for RHD (UK) models.

5.0L models have two backup lights.

 

Excellent point Stuart!

 

Yet another reason to put the 5.0 SC into her...