According to Official Guinness Records,
The largest breakaway glass structure smashed by a car measured 23.91 m² (257.36 ft²) and was achieved by British stuntman Rocky Taylor (UK) for Remember A Charity (UK) at the O2 Arena in London, UK, on 13 September 2011. Rocky attempted the record as his "final stunt", aged 67 years old. He has been a stuntman for 51 years, appearing in James Bond films (doubling for Roger Moore and Sean Connery), Harry Potter films and Titanic. He drove the car at approximately 50 mph, before speeding up a pipe ramp and smashing through the glass structure. He then flipped the car and landed upside down on a pile of parked cars. The record attempt was staged for 'Remember A Charity', a charity which encourages people to leave a lasting legacy by leaving a donation to a charity in a will.
For a complete list of 2011 records, please visit 2011 Guinness Records in United Kingdom.