After researching things further, I came to the conclusion that it's just not possible to simply bolt on an exhaust tip.
1) The tail pipe (after the resonator) is flared at the end slightly
2) The pipe is curved downwards too much
So, I thought, why not shorten the tail pipe to eliminate these two problems?
Good plan - in theory. The reality is, however, that once the curved, flared portion was cut off - there wouldn't be enough pipe left to securely bolt an exhaust tip onto.
So - it appears that the only potential options left are:
(i) Get a muffler shop to cut the pipe off after the resonator and weld a tip onto it. (I need to research this further to see if it is even possible - although it should be)
(ii) Get a muffer shop to cut the pipe off before the resonator, ditch the resonator and then get them to weld on a length of pipe with a hanger and a tip. (I know this can be done - but I am unsure about the emissions ramifications of ditching the resonator if any).
(iii) Purchase a ready made, Sorento customized pipe and tip to install from the main muffler back. This again involves ditching the resonator. I have seen these on other forums, but the souce web site for this part is down. This is also alot more $$$$. (these simply bolt onto the pipe that exits the main muffler)
My personal preference would be (i) but as I said, I need to investigate the option further. Once I do - I'll post.