Welcome and enjoy the car. As far as a tune, I run the cobb ap . I'm not trying to sell you on one or another , but like someone who posted earlier said you can't go wrong with any of the major tunes. I do like the ease of the installation of the cobb or uninstallation when going to the dealer as my car still has a little over a year on the cpo. When I first installed my cobb on stg 1 agg. it netted me 70 whp/ 80 + wtrq on my 335xi with 6at. GLW your choice.
volk re30 18x8.5 / tc kline coilovers / cobb ap / afe stg 2 sealed cai / afe air scoops / 5" ets fmic (sold car)
2013 x3 35i fully loaded with M package