Thanks guys. "Everything should be as simple as it can be, but not simpler”.

Yes, I will hang the tailpipes under the trunk floor somewhere (can't use the frame rails since with the minitubs the springs are directly under them).

Another issue - My Summit X-pipe kit is several inches behind the front U-joint of my 3.5" driveshaft, and can't be much further forward because it would hit the safety loop. So the X has to clear the shaft with the rear suspension at full extension. Is this going to be the low spot under the car (or will I be scraping the mufflers on speed bumps instead)?

I guess it doesn't really matter since the exhaust system has to go somewhere... it is what it is. With leafs/Caltracs and 295-50 tires on 15" rims, ground clearance should be OK. We shall see.