I just found the other episode, where Dan and Ros get stuck in the elevator. It is Season 4 Episode 9 "Earthquake"
Dan starts to explain why he is claustrophobic and says, "I got stuck in a drainpipe."
Ros responds, "Too cheap to spring for a motel?"
Dan starts to explain why he is claustrophobic and says, "I got stuck in a drainpipe."
Ros responds, "Too cheap to spring for a motel?"