A car dealer in St. Louis is advertising that, if you buy a Chevy Cruze from him, he'll give you a $300 gas card. In the commercial he claims, "that's a free tank of gas every month for a year!"
While the Cruze is a fuel-efficient vehicle (its Eco model supposedly gets 42mpg), the math is wrong.
The Cruze comes in five models, four of which have a gas tank with 15.6 gallon capacity. The smallest (Eco) has a 12.6 gallon gas tank. At $300/year, that's $25/month. At the current price of $3.15/gallon, that's not even 8 gallons/month, let alone a full tank. The only way the gas card value works out is if you drive less than 300 miles/month every month all year.
I'm not saying the Cruze isn't worth buying, nor that $300 in gas isn't worth something. But if this dealer can't do the math on this correctly, you might want to double-check all the numbers on your sales contract when you buy a car from him.