I've seen a lot of people asking about audio upgrades. DAB gets a mention as does keeping the steering wheel controls. I'd like to propose that you contact a UK company called Connects2.
I have no direct personal affiliation with the company but I do know someone who works there and I know they work very hard to provide such Audio solutions for all make of car including Hyundai, if you contact them and discuss your requirements they will deal directly with your needs wherever they can. I know who the main UK distributor is and I have enquired about Southern Hemisphere outlets too, I'll Post up when I get that info as well as pan European contacts.