I doubt it was in a cab -- but trust me -- she stayed at the RC (it's the same for HK btw) -- but in London she will only stay at the Langham.... Don't ask me how I know - but here is a picture before she went out to the press in London a few years back -- that's the Langham lobby before she walks out in front of the BBC... Just google Lady Gaga Langham to see what it looked like outside... Every night it was a different outfit lol!