V.W.
Based on the driving you suggest they are likely doing, then unless someone is stealing it (syphoning it off) then I'd be suspicious. I used to spend that fairly easily, when I was transporting my kids to and from school 30 miles away 5 days a week... so 120/day every day, plus after school stuff... I averaged 800 miles or more a week... and my vehicle gets about 20mpg. 40 gallons of gas per week at $3.50/gallon is $140 per week. So... yeah... in 13 days, I could spend that. But not driving ANY kind of car 6 miles to town daily.