Destroying exhaust manifold does not break turbos.

On the SBR4, you can rip the exhaust manifold out of the car and the turbos will still function. Just a small oversight that should be fixed.
I'm driving around with the exhaust bits (turbos included) on top of the car, yet still producing max boost.

 

I guess this would need yet another extra break trigger beam to be included.

With many changeable parts then it would need to optional and only when part is not present etc. Hence complexity grows fast.