Thanks for all the comments folks. I don't think I would have a problem lifting a bike on to the roof of the car I'm fairly capable .
I said to the wife last night I was asking here about the roof carrier. She went a bit daft , no way she says .im not driving about with a bike on the roof .it will look stupid and too high . Personally I think she's right it will be high as the cars a Tuscon but I've seen plenty of high cars with them on . I can't justify the money for a tow bar being fitted as it wouldn't be used so only other option would be a rear mounted carrier. I would probably spend the same money on a rear mounted carrier and roof bars and a mount . So it might come down to which is less hassle to fit the bike on? Still think roof mounted as I probably would use the roof bars for other things .