2inch is very large for a stock engine. That's why she's so noisy, it also flares after the tail pipe (the part that follows the exhaust manifold flange) so that setup is mostly for noise. Won't offer much benefit and would most likely hinder performance (slightly) due to the lack of back-pressure (queue jmac to explain the importance of back pressure etc or re-think your understanding of the term extractor).

It does look small-ish for a 2 inch setup though, did you measure across the pipe or across the angle cut at the end? (no offense but you'd be surprised).

Your pal with the Lotus would be very right in saying it all has to happen at once as much of the gear in a lotus the may actually not fit without replacing/modifying all the componentry, that and the fact that his mechanic may realize he has more money than the average JD so he simply insisted he get the lot (both parties win).