This is a discussion on Car charger within the iPhone 4 Accessories forums, part of the iPhone 4 Forum category; Hi All,
Can a car charger for a 3G/3Gs be used with a IP4?
The connectors are the same right?
Yes, the connectors are the same but it will work depending on the charger. I have two which were used for mine and my wife's 3GS of which only one works on my iphone4. Also, some may work on the iphone4 but take twice as long to charge it. My recommendation would be to buy one from apple or AT&T and avoid the $.99 ones on eBay.