Whether you envision having a huge photo laid across the entirety of your vehicle or if you just want a few select images incorporated into your design, here are a few things to consider first.
The first thing to keep in mind is that your car is a rather large space to cover considering the overall width and height of your car. So for starters that picture you took with your everyday point and shot probably isn’t going to cut it. So with that in mind, image resolution directly effects image quality. Generally a higher dpi (dots per inch) is always better, but keep in mind that has its limits too. A 300 dpi file that is 1 inch by 1 inch is not going to work very well on your wrap. It is a combination of dpi and size (at that dpi) that dictate if a photo will work on a wrap. That is why your point and shoot will not typically do the job, most are made for taking pictures to print at normal sizes: 4 x 6, 5 x 7, and 8 x 10. Photos should be taken with a professional grade camera at the highest allowable resolution and size, especially if this image is going to cover your entire wrap.
Image orientation and composition also plays a big role when determining if a picture will work for a wrap or not. You need to take into account how the picture will lay on the vehicle and make sure that something important is not going to land in an area that cannot be wrapped (i.e. the front driver and passenger side windows). This way nothing is abruptly cutoff, like part of someones face or part of your product.
With these thoughts in mind, you may want to consider buying stock images or hiring a professional photographer to take photos you need so that they are displayed crisp and clear on your shiny new wrap.