According to Official Guinness Records,
The fastest 20 m wife carrying backwards is 9.82 seconds and was achieved by Manav Gohil and Shweta Kawaatra (both India) on the set of Guinness World Records - Ab India Todega in Jogeshwari, Mumbai on 18 March 2011. Manav Gohil and Shweta Kawaatra are both starring in a daily soap.
For a complete list of 2011 records, please visit 2011 Guinness Records in India.