I'm planning on dyeing a set of grey seats black.

What's the best type of dye to use? I want it to not fade, look patchy or go crusty. And I'd need to use like five or six bottles of that SimplySpray stuff, and I don't want to pay $120 to dye them.

I also want to dye some carpet, because I can't find it in the colour I want.

I was going to try and dye carpet, but couldn't find one that would stick to synthetic materials and stand up to wear. Ive heard that the VHT vinyl dye is ok for carpets that don't get wear (e.g. door pieces, parcel shelf) but not for the floor. Can you sew at all? Might be worth finding a cheap set of 2nd or 3rd gen seats and taking the covers off and making new seat trims out of material the colour that you want since dye isn't really that cheap either.