Which is better, BMW Z4 or Audi TT, suitable for racing and modification?

Personally, I think the possibility of TT Z4 modification is basically zero, unless it is only a shape change and some kits. The cost of mechanical modification is too high, which is determined by the concept of German cars. There are about 70W sports cars, including Z4 TT SLK Porsche boxster and Evo GTR 350Z in Japan. In terms of performance, GTR is Wang Zhongwang, with the same mechanical level and similar appearance as the supercar you mentioned. Very fashionable, but without German cars, the performance of noble EVO is much worse than that of GTR, and the price is several hundred thousand less, but it is enough to drag. After all, it is rare that GTR 2 can run 120 and meet his road conditions. The reason why 350Z is beautiful and avant-garde is that the mechanical strength produced by GTR is not much different. It is recommended to modify EVO, because GTR is too powerful and the road conditions are not allowed. Without modification, Porsche boxster TT can personally think that TT has DSG dual-clutch gearbox, and turbocharged Quattro is better than Z4. Z4 SLK is strongly not recommended. Others can search for pictures and compare them. In short, TT and boxster are recommended.