ROFL, I just watched the episode last night. He cancels his vacation so Brian can go to Drug Rehab and decides to join up.
One of my favorite Quagmire lines is from that episode.
Brian is sniffing people coming off and Quagmire is like, what do you smell. I smell 2 asian women.
Quagmire: Thats Right
Brian: and a man
Quagmire: You mean 3 women
Brian: sniff, No
My favorite Quagmire line is in the episode where Peter finds out he is partially black. He walks in on the cheerleader Stewie tied up in the bathroom "Dear diary....jackpot."