I have removed both TCA's again from the car. This morning I had the bushes flattened at work so that they now are the same length as the metal pins inside. I measured the original rubber bush and also the inside of the subframe. Both saw a distance of 51mm. The metal pin that came with the PU bush also measured 51mm. But with the bushes in place the total measured about 54mm. And 3mm of PU squeezing together is a lot!

So now both bush and pin are 51mm when put together in the TCA and I am going to put it under the car tonight.

@ robocos: Maybe you can try to move the car on a kerb with only the front tires so you can get under it.

Thanks for all the good advises guys. I will let you know as soon as its all fitted.