Dealers generally wont just put you the map on tbhI'm considering trying and do it myself with the a kit you seem to be able to get on ebay for around £20-30 with a cable and a probably illegal copy of the bmw software
but there is a risk of bricking my ecu so might see how much the dealers would charge
that was the other reason i was looking at going do the route of doing it myselfDealers generally wont just put you the map on tbh