If you haven't already got axle stands and a hydraulic jack its worth investing in these to get at the underside in relative safety. There are many things you can do that a servicing garage may not have on their agenda. Adding my two pennyworth I suggest greasing the spider universal joint at either end of the prop shaft, also the similar joints on the steering column, squirt some bike chain oil onto the rear springs too. Replace engine oil drain and gear box drain plugs with magnetic ones. You might be surprised to see the metallic sludge drawn down at each oil change. My 2008 4/4 has now clocked up 91,000 miles.
