Domstrebe with serial suspension – is that possible?

Hello guys. I ride with my Golf 5 GTI sometimes at such motor sports events. On the whole it is not bad, but in long-drawn curves the box underruns a lot. Very annoying if before me a 3 golf with hard chassis runs through the curve much, much faster than I. Then I bought R-tires. It is a little better. Unfortunately, no other chassis can be built in my GTI, since I already have the 11cm ground clearance (STVO in Öster) in standard condition. Now I wanted to ask if event. a cathedral trespass brings something. Front top, bottom front, back or all 3? What can you recommend to me? PS: Would you like to drive with the GTI, because I have no money and space for a 2nd car. Would be happy for your advice. mfg Mario