underbody sheild

Hello i was just wondering how much of my 2006 x3 should be covered with a under body shield right now the front shield covers maybe a bit past the oil nut and there also a shield towards the end but the middle of the car is exposed is this normal? (By shield I mean the Hard plastic that covers the bottom of the car)

The plastic one is connected to an aluminum one in the area of the transmission/frt. diff./transfer case,
and no continuous underbody protection from there back as you noted.
Maybe some sort of skid plate under the rear diff. - not sure on that.

Make sure you have plastic pads on all 4 jacking points - missing ones are indicative of undesirable or unplanned off-road excursions.