sa, I've dried staves in my car too but they sometimes warp and check badly, especially when they are very green. Some wood, like ash, will dry out nicely in a hot car. Google the type of wood you have and try to find data on how fast the wood will kiln dry at the lumber mill. It's no coincidence that most lumber available at the "depot-type" stores is wood that can be force-dried quickly.
There are also many references that show that a sinew backing can be force-dried with heat, although I don't do it myself. The climate here in west Texas is dry enough.