I removed my airdam on my 07. Decided to leave it off.
I think that the owner's manual recommends removing the dam before going off road.
I have not measured but I think that to do so grants you a little clearance.
2007 WK CRD, Quadradrive II, OEM Tow Hitch, GDE EcoTune, DPF-Delete, 4xGuard Front, Rear, Belly Guards, Side Rails & Full Matrix, OEM Skids, EHM, Dash Duck.