If you can find a tow bar kit for sale it's actually not that bad to fit to be honest. And even the non removable ones like mine only have 2 bolts to undo to remove the bar so not so bad if you don't want it on there and a snip of the price of the genuine removable jobbies.

theres only going to be 1 bike on it and it's a featherweight sub 14kg so the loading would be quite low. I have run with the bag idea, I will try some bike "plane" luggage as my start option (keeps bike most secure!), boot mount as 2nd choice (already got one)followed by a roof bar investment. As for new bike....it is new and I really don't want to swap it until I've fallen off it a few times!