Luckily I don't have to deal with this little tidbit, but if you live in a place with your garden variety pit viper (copperheads, rattlesnakes etc.) You might just want to grab a handful of gravel and toss it under the car before you get in. A mild winter and a warm spring has these guys overpopulated. I know when it gets cool later in the year, they like the heat of your car engine. Cools down at night. Toss a handful of gravel.
http://www.cdc.gov/niosh/topics/snakes/