Parts to upgrade lower spec Kia's to higher spec models are not normally available from dealers. The normal route appears to be to source parts for the scrappies or e-bay.

But as for doing the work yourself there is a catch, you will loose the electrical part of the 7 year warranty and we all know how expensive and difficult electrical faults can be to fix.

One poster on the Kia forum had an assurance from Kia that providing a dealer or electrical specialist carried out any radio upgrades the warranty on the rest of the system would be honoured but they needed to retaining receipts detailing the work and costs and the company had to be VAT registered.

Since the 7 year warranty is a major reason people buy Kia's (especially used ones where the remaining warranty can be better than many other new cars) you don't really want to jepardise it.

But the posters on the Forum who buys cars where the previous owner had either tampered with the car or not serviced it and lost the warranty never blame the previous owner so you would be in the clear. They always blame Kia threatening court action saying they will never buy another since they are rubbish cars.

If you only need the USB for charging phones etc, a cheap adaptor that plugs into the cigar lighter socket is available very cheaply on fleabay

And in Poundland.

Be careful of very cheap ones they can and do overheat