As far as why people don't go to local muffler shops, I'm sure many do. But you have to keep in mind a local muffler shop will build an exhaust with 1) crush bent pipe which is restrictive 2) use mild steel, aluminized steel or at very best 409stainless which isnt really stainless by our standards, and 3) will cost you 500-1000 depending on the shop, quality of materials and time. The EMSPowered system is a setup 1) built and tested by a company specializing in Land Cruisers, 2) built from 304stainless, 3) mandrel bent tubing, 4) has proven dyno tested power gains, 5) uses high quality fasteners and materials. A system equivelant to the EMSPowered catback built by a local muffler shop would cost around $1500-2000 if a muffler shop were to build you such a system. That is even if you find a place that is capable of building such a system and is capable of properly TIG welding the assembly.