Thank you so muchbto everyone who has replied so far. I have looked on Skoda Parts and the factory fit are 3Q0 511 115 AL, so the fourth on the list. Very useful to know what I would go up to. To answer the question of sag, it's probably a mixture of boarderline overloading, plus distribution. We have small kids who don't weight much over the axle, and then the heavy stuff like a 60kg air tent and towbar mounted e-bikes sticking way out the back, which has made both previous estates sit low. The air springs are on option for the Superb but I think about £600 fitted, which is probably more than I want to pay. So my choice is between going to the N spring, or the Mad helper springs. The former is a lot cheaper. Does anyone have an instinct as to which will be better - the best compromise between comfy as normal unladen, and as level as possible laden? Thanks again, James