Ashley Baker, who is originally from Cookridge and now lives in Bradford, was returning from a family holiday in Cornwall with his partner Laura McEwen, 26, their three-year-old daughter Niamh and eight-month-old baby Isla when they saw smoke coming from the bonnet of their Vauxhall Meriva.
Ashley, 28, managed to pull onto the hard shoulder - and just two minutes later the vehicle was engulfed by flames and completely destroyed.
The terrifying incident happened on the M5 in Somerset on Sunday afternoon.
"We were driving back to Yorkshire after a lovely family holiday in Cornwall when we started to suddenly lose power and smell smoke coming from the car. We managed to get over to the hard shoulder just as the smoke started to billow out.
"We had to drag our daughters out of the car as the flames had already taken hold. If it was 30 seconds later it would have been a different story with how quickly the car became an inferno.
"I have never in my life witnessed a car go up in flames so quickly and it was a terrifying experience. The fire brigade and police were fantastic, especially with the girls, and we couldn't thank them enough. My three-year-old is devastated. We lost everything in the car but the main thing is we are all OK; material items can be replaced, lives cannot be replaced."