Ahhhhh....dog hair! I have 2 mutts myself (both rescue's..pitbull mix and the world's goofiest black lab LOL).
I just did that red X5 that had a lot of dog hair and used the following methods: vacuum, vacuum with a brush attachment, vacuum and finally take some duct tape and reverse it to dab the carpet for any hair the vacuum missed. The tape also works well in seats, corners, etc. I also don't get anything wet until the hair is removed as it tends to bind with the carpeting, etc and is tougher to get out.
I probably spent 45 minutes getting the hair out of that X5. There might be a couple of strands left for the CSI team to find (if Grissom is that good....our company supplies some of the props to that show).
Toto