taking the clearance lights off to fit in the garage is ridiculous, lowering an H2 is ridiculous-sorry just my opinion.

You are going to spend quite a good chunk of change for new suspension parts to lower an H2 not to mention it will look completely terrible.

And the factory air suspension is only on the rear-Land Rovers/Range Rovers have full air suspension all the way around-H2 is not the same system.

 

Get low profile tires on 17 inch rims

 

You could also give your Mom back her Hummer. That would be a quick fix. I agree with the other poster, just go get a few hundred dollar gas mileage beater if you dont like the Hummer.