Ronnie, 47, from Ruislip, pictured, and Gary, 53, from Hillingdon, are the latest in a long line - or is that rank? - of people to strip for a good cause.
They are Mr February and Mr March respectively in a 2012 calendar raising money for the Suzy Lamplugh Trust, created by GetTaxi, a company that allows people to book a black cab and see the drivers picture, name, mobile number and registration number, as well as track its progress to you in real time on a map, all via smartphone.
The idea is to promote safe taxi use, and GetTaxi drivers operate a 'closed door' policy, whereby they wait until a female passenger is safely behind a closed door before driving off.
It hopes the phone 'app' will be popular with women, who can use it to safely use a black cab, from booking to home.
So what was it like getting naked in mid-winter?
Lets just say I wished wed chosen to do this in July!," said Ronnie, who with Gary and 10 other London taxi drivers posed for a group shot close to Tower Bridge a few weeks ago.
"Although we were all a bit nervous it was actually great fun, and Im happy to be involved with something thats raising money for such a good cause.
Just don't expect him to pick you up wearing nothing but a street sign.
 The calendar costs s3 and is available from www.gettaxi.co.uk