Rich,/ list All of the info will be up on the exhaust website soon www.stainless-exhaust.com and also on our club website when we gat a minute. www.delorean.co.uk The car we used on the Dyno trials was my very low miles LHD 83 car, recently brought back into use. The speedo was showing 135 MPH on the Dyno ( 170 one fitted) and with a car that had only done 111 miles from new, it must have wondered what was happening to it! The results are:- Stock system...............120 BHP ( only) new system with twin cats 135 BHP New system without cats 142 BHP ( If you want me to send you the 3 graphs contact me direct at cp@xxxx) This was on this one car, it may not be the same for all cars, no guarantees Etc. Etc. You should really talk to the manufacturer for prices, but the UK system is 650 GBP ( about) 950 dollars plus shipping and any taxes your end. The twin cat system is about 920 GBP (1350 dollars) plus shipping and taxes. Polishing is available at about another 75 dollars. I must stress that we helped the manufacturer develop this system, We are very happy with the results, especially the craftsmanship and finish of the finished system, but any dealings must be direct with him, and not through the UK club. We have no financial or other interests this matter. Best regards Chris P DOC UK BTW I would go with the "medium loud" system, the very loud one is probably illegal and certainly not restful!