Walloon

Hi all, new here and hoping you can help with a radio question from a newbie. I'm looking to get a 2nd hand Roomster soon. It looks ideal - apart from the lack of bluetooth/DAB on the radio. I'm not bothered about phone calls, sat nav, touch screens or full integration, I j ust want to be able to connect my iphone so it plays music over the car speakers, & having DAB would be nice too. I assume I'll be able to play music with the stock Roomster radio by plugging a cable in from the phone to the car, but since apple removed the headphone socket on the phone i'd rather have the socket on my phone available for charging. Can you get a dealer/garage to upgrade the radio to a VAG one with bluetooth? At what sort of cost? And will that still work with the parking sensors etc? I'd prefer to get a VAG radio rather than a third party one, or at least if it is third party something that matches the dash and doesn't look out of place. Thanks