Thank again Tommy. I'll bear those in mind
Back on the subject of my original question tho, I have a bit of an update....
In preparation for my visit back to where the Lifeshine was supposed to have been done, I did my own test and squirted water on the door that I had done myself (tar removal, SRP & G3 wax) and on the adjacent door that (should have) just had the lifeshine on. There was definite difference between the 2 ie the water on the front door that I had done beaded a lot more than the rear door.
I also squirted some water on the rear seat, on the alcantara, and it just soaked straight in; no beads whatsoever, as suggested there should be by the AutoGlym bumpf
Back at the garage, they were fairly sure it had been done but accepted I wasn't happy so they redid the Lifeshine anyway. When I went back to pick it up, sure enough it did feel a lot smoother.... on the easy to reach surfaces
It did look like they hadn't buffed off all the wax/finish properly as it was still a bit greasy in places, and you could see smears where you ran your fingers across the paint, but at least they had appeared to have put something on there this time.
But in the heat of the moment, I forgot to ask whether they had done the interior
Back home tho, I ran my hand along the lower part of the rear door, next to the one I had done, and it was still a bit rough in places as there are still tar spots there, but not on the door I cleaned last weekend
Oh well, looks like i'll have to do it myself, again...