I would recommend a different USB part:

http://amzn.com/B0082CXEI8

It is panel mount, so it will look nicer and is self-trimming. It has two USB ports and has leads so you don't need to disassemble or hack the part. It just works.

Most importantly, it is rated at 2.1A (max you want to go on a 10A 12v circuit is about 3A), so you can charge iPads or charge iPhones 2x faster.