[NikosF]

I've just had one installed. I didn't do the install myself, but the workshop I took it to, said they only had to elongate two of the bolt holes slightly to make it fit first time.

I had some other suspension work done at the same time (Koni shocks, and rear suspension bushings), so it's hard to isolate the effects of just the stiffener, but for me it was worth it. The car feels dramatically more stable over rough surfaces. Before I could actually feel the car flexing - now it's as stable as a car with a roof.

Now - whether it's the first $450 I would spend on a $700 Spider is another question. I would first replace the bushings and shocks and make sure things like the tie rods were OK, and the camber and toe-in were set correctly. Once the rest of the suspension is sorted, then think about the stiffener