XD's are difficult. If you plan to drag race? I'd suggest 2 1/2" upto just before the diff with flanges. From the flange back run either 2" or 2 1/4" pipes over the diff. That way you can remove the small tailpipes when you race
Also quietens it down on the street.
I am pretty sure a creative exhaust fitted can squeeze a twin 2 1/4" under anyway. Most fitters worry about the plastic tank. They forget it's heat/flame retardant plastic. As this is a requirement for ADR of plastic tanks. Thge likely hood of melting a tank is very unlikely. Considering the XD is still a leaf spring setup it can't be that hard can it
The other thing if my memory serves right is the tank is offset to one side. So the idea is to have both pipes popping out the same side like a new car does
Problem solved but more work for them and they don't want to know about it usually. Ask about running twin pipes in a similar fashion to the new cars. See what happens?