Trade our E46 touring for a new Jetta TDI Sportwagen?

I had an interesting idea...sell our '03 325 touring for a new or 2010+ Jetta TDI Sportwagen. Our touring has 108k miles and has had most of the usual issues sorted out but will eventually need a new alternator but runs and shifts fine. It is also our doggie transport vehicle. One reason for considering a swap is the new 2015's will require the urea additive where the pre 2015 TDI Golfs and Jettas do not. Obviously there are trade offs but probably keeping the BMW would probably make more sense. Comments or thoughts?