Rednroll

Yeah, the newer RHR's only have 1 rear USB connector. As you may or may not know, USB hubs....which is all that is, inside of the RHR, only have a limited amount of power to distribute between the devices that get connected to them. So, I'm guessing on the earlier versions that they may have run into a problem where someone tried to plug in an iPad, and 2 iPhones and then complained because all 3 devices would not power on through the radio's USB connections at the same time.

Apple's devices require 1 Amp of power draw. Take notice, USB 2.0 specs call out that a device must limit itself to 500mA of current draw......half of what Apple's devices will pull. However, Apple makes their own rules and expect everyone else to work around them....even if that means they violate the USB 2.0 "standard" that everyone else designs their products to. So anyways, typical hubs provide just over 1 Amp total to all their individual USB ports. I'm gonna guess they removed 1 of them for 1 of 2 reasons.
1. Chrysler decided they weren't going to have 2 additional USB connections in the vehicle, so had one removed out of non necessity.
2. Apple is to blame for being USB power consumption hogs and the rest of us must suffer by Apple violating the USB 2.0 specifications. Thus, remove a USB connection port to avoid over power consumption problems when connecting multiple Apple devices to the same hub.

Go ahead, try that at home on your PC. Plug in a non powered hub into a USB port and then plug in an iPad and an iPhone at the same time into that hub and see if they both still communicate with your PC.

P.S. I'm not an Apple hater.

Sorry, had to make that disclaimer because the last time I made a minor criticism about Apple devices, some Apple fanboy came out and went all fruity on me. I actually own an iPod Classic, iPhone 3GS and an iPhone 5 and looking to invest in either an iPad or iPad mini in the near future. I just work in the development of electronic products where their are industry standards to follow and am all too familiar how Apple breaks these industry standard rules that everyone else follows and since Apple is currently king of the electronics world, they seem to get away with it.