iPhone 4S extra phone numbers when synced

[Supernut58]

I have an iPhone 4S and when I sync to my car, old deleted phone numbers that are not listed in my iPhone show up in my cars phone book. I have made sure that these contacts are not in my email contacts or Facebook contacts. This is a old number I deleted some time ago. Is there a way to backup my phone numbers and wipe my phone and then reinstall my stuff?