MKS owners don't know how to use the Internet, so you must be the only one that figured it out! I keed, I keed

Welcome! Post up some pics!
A '13+ MKS EB is sure rare, love seeing them on the road once every 6 months! I contemplated getting one due to the pano roof, adaptive suspension/HIDs, and lane departure. But in the end, went with the sportier looking SHO that matches my age better (33).
A $500-600 tune+3BAR MAP is your best first mod. Will add 60+HP and 75+ lb-ft of torque, good for a 13 flat @ 107MPH yacht! After that, down pipes and a full exhaust are recommended. Should get youa 12.5-12.6 in ideal conditions. Then after that it's adding a meth system so you can up the boost/timing and will be in the low 12s. These numbers are based on SHOs, so might be 10th slower on the heavier MKS.