It is 13% if you are mil and based in UK - could be more obviously if you are Germany/Cyprus. I am pretty sure that the Forces Disocunt Directory covers Land Rover and mentions that number. I looked at buying one a couple of years ago and was offered that discount.
If you had tried to buy a new or used RR a couple of months ago you could have named your price as they could not shift any. However, I see that the price has recovered a bit in the last month. I had looked at replacing my current RR with a new one and am kicking myself that I didn't go for it in Feb/Mar when they were selling new RRs for over Â£15k off the list. Still worth a speculative offer at a LR dealer as they are struggling to shift them in the numbers that they had become used to.
Had the same thing with an RS4 from a main stealer. Wouldn't shift on the price and yet six months ago were desperate to sell and Brum Audi eventually lopped Â£4k off an Imola Yellow one to offload it. Mind you, anyone brave enough to buy and drive yellow RS4 Avant deserves a discount!