window seal

I'll swap this https://www.youtube.com/watch?v=eW_1NEMcYIY&feature=related for information about where I can get a seal for the bottom of the window on a door. Mines broken off a bit so I've covered the hole in tape to stop water getting in and making rust!! Not an ideal long-term solution.

Drivers or passengers? I have a box with loads of bits on I think I have a seal strip but will have to have a look failing that measure it for lenth and get one from anything that is the right lenth or longer my Escort needed some and I just found some longer ones and trimmed them down to fit.

Driver's side door.

Can you buy it "on a roll", so to speak? Is this a case of going to Halfords or similar?

No it is metal coated with rubber if you do make some don't worry to much about a good seal they are onlyu there to deflect the majority of the wet stuff there are drain holes at the bottom of the door for the water to run out.