Side exhausts fitted to my S1, also had the s3/S4 diffuser fitted as well.
Look really good.
Exhaust boxes much smaller, but quiet at tick over and light throttle, but nice and noisy when accelerating hard.
Infinity exhaust fitted the side exhaust, stayed with the original cats as I think sports cats may have got the MIL light glowing and it's plenty noisy enough. Infinity do the sport exhaust for William Morgan. I used the standard Morgan aluminium trims, so the exhausts look the same as a standard S2 etc.
Brian Miller fitted the diffuser, it looks really good and looks like it was designed for S1. Needed a bit of fettling to fit, took him 5 hours, but great job.
If some one can post the pictures, I'll email them across.
Regards
Andrew