Roof rack? Something by Thule.
Tow bar? Something by Thule - these are excellent.
On the back, on the bodywork? Saris Bones, though it is expensive.
I'm driving. BMW e46 saloon
Not sure I'm happy with a roof system tbh ... Don't like the idea of bike on top
Just watch out for car park heigh barriers Whilst they make it easy to get the bikes off the roof, it's an expensive shortcut.