How about Meredith & Gretchen? (old couples team <3333333333 along with Bill & Cathi)
I think Meredith & Gretchen make into the F4 due to the streaks of luck start from Africa leg to their elimination.
South Africa: Saved by NEL (though OMG at Gretchen got injured badly)
Botswana 1: Brian & Greg flipped their car and Ray & Deana incompetence bickering
Botswana 2: No bunching point, Brian & Greg couldn't recover from the incident last leg
India 1: Saved by TBC
India 2: Lynn & Alex got lost to the Pit Stop
Turkey: Being on the REAL earlier flight to Istanbul with the help of Romber prank on them about the FAKE earlier flight.
England: Luck ran out and eliminated. They have chance to survive this leg if they gamble to take the flight to London by connecting in Frankfurt on standby tickets and/or Romber yield Uchenna & Joyce instead of Ron & Kelly.