We had a 2004 Octavia 1.9 TDi 130 that went like stink. Adding our (nose light) Pageant Majestic S5 it made the back end sink.
I fitted the UK equivalent of MAD (at that time were about £89) with some from Grayston Engineering which cost me IIRC £66. They did lift the tail a bit but the ride improvement was really noticeable but with the caravan on as well - magic! One of the smoothest tows ever. Per fitting, once I conquered how to do the first wheel (which took nearly an hour) the second fit took about 20 minutes from start of jacking up to grounded and finished. You need a lift jack and sockets and some blocks or a (single) ramp. Remove the wheel, disconnect the shocker and let it hang, and jack the car up a bit to make sure the suspension spring is fully extended. Fit the bottom cup in the bottom of the spring, then wind the new additional spring through the main spring to seat the aux spring inside it. Put some blocks under (I used a ramp) to take the body and put the jack under the spring and pump it up until you can reattach the shocker. Remove the jack and put it on the body lift point to raise the body and remove the blocks/ramp. Refit the wheel, lower it and recheck the wheel nuts preferably with a torque lever - usually 80Nm for a metal wheel or 130Nm for alloy.
However in much more recent times we have had three Passat estates which use the same chassis as the Superb and that is a whole different ball game. The rear springs sit in the well of a (square) u-shaped suspension member, which means that you need a spring compressor to be able to keep the spring slightly compressed so that you could lift it out and fit the MAD part inside it. In the end I got my local tame garage to fit them for me