I loved my 300 tdi auto. Tweak the fuel pump and turbo a tad and they are fine.
As long as they have the diesel auto gearbox in them.
As with any secondhand car buy, try and turn up a little early.
Start from cold.
Drive it a reasonable distance.
Personally when test driving an auto I drive it a bit harshly, checking kick down as well as manually changing from 1 to d revving it out a bit and selecting the next gear.
Auto box when warm or cold check for.T
Thunk, clunk, slipping, ( not technical terms but you own a landrover so will know what I'm talking about) gear selection. Does it change smoothly, not jerking into gear or sort of slipping in and then biting?
Gently come on and off throttle to show up any lash in drivetrain.
Most old autos are a little sluggish from cold as very few people change the oil and filter.