If you have access to a plasma cutter (or some other cutting device) try this.
Cut open your gutted main cat, place a pipe straight thru it, then weld that to the flanges and bolt it back up. You retain stock look, lose any turbulance and have an off road pipe that looks like a cat. IIRC somebody had their Contour smog checked Catless in CA an still passed the sniffer test. Normally I don't agree with removal of polution control systems (indeed I would love to see race cars of all sorts forced to use some sort of polution control so they can get some really good technology for street cars....) But seeing that the Contour is a very clean running engine....