I have one of the locking tools the chap was spamming.
Its cheaper than the landrover part, and it does the job, but the welding is shocking on it. Proper sausage of mig, with so little penetration that it looks like you could knock it off with a chipping hammer.
I mean it does the job, but at 60 quid or whatever he is charging, he should maybe go on a welding course.
Irritatingly the week after i bought it, a landrover one came up on ebay 2nd hand.
I have done 300tdis without the tool, but it does make the job a lot easier, and less random.