How to get the smell of weed out my car?

So my brother used my car for the last month and it stinks of weed now. I have a MOT tomorrow and I have to get this smell out as much as possible. He never told me he smoked weed I am so angry with myself. I gave him my car for uni work and his other job. How can he disrespect me like that???? Anyways, how do I get it out ASAP? X