I use the 591 with my Vantage which is almost the same shape.
You can move all the parts around on the main bar to make it fit better. Including the lump the arm is attached to. Take it off the car and loosen everything off. Put the bike in and move it all till it fits.
591 has now been superseded by the newer version (probably 592)
Should be pretty much the same to sue but a bit “better”. The clamp should go just before the BB on the down tube and sit behind the chainring.
The Thule racks should fit any type of roof rack with the correct fittings. You normally have T slot which can vary in dimensions between brands and absolutely do not bodge or the semi-circular clamps which go around the bar and are intended for the steel square ones.