Why do people in this part of the country like burying cars so much?

Fifty years ago to the day, the city of Tulsa buried a Plymouth Belvedere into a concrete vault under the courthouse lawn. Part gimmick and part time capsule, people were invited to guess what the population of Tulsa would be in 2007 with their entries locked in the car's glovebox. Today, the car was unearthed and I think the winning entry is supposed to be revealed tonight. The winner gets the car and a $100 savings bond that was buried in it, which over 50 years of appreciation is worth a whopping $1200 or so today.

Unfortunately, ground water seeped into the vault over the years, and what was pulled out today was a rusted relic full of water and mud. Regardless, though, it must be cool if you were a kid that witnessed it being buried back in 1957 and had the opportunity to watch it being unearthed today.