Aero's with sidepipes had definitely be careful.
The S2 with the single pipe has failed a drive by test at a track and I was told not to bother trying with the Coupe.
With standard exhausts the Plus 8 "just" passed the test at Castle Combe.But that was in standard mode and not moving. When driving in Sport Mode it is a lot noisier and has pops and bangs.
It is my understanding that a vehicle has to meet the dB value on the V5, or its homologated reading. Over the years permitted levels have reduced, so older cars can be louder.
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