My 2010 xc60 t6 r-design with 120k on the odo is blast to drive. Had the local delearship do the Polestar tune to the computer and I have my nifty polestar badge on the car. Should I add a cold air intake or just a K&N filter? I have already taken the foam off of my current air filter. Is it worth the money for sound and minimal hp gains or spend on something else?

 

I wouldn't do the K&N. I don't think that they filter as well.

 

I wouldn't do any cold air kits. With modern cars, they make more problems then they solve.
Stinky is absolutely correct about K&N. There is a reason they let more air in. They allow more particulate matter through too. That, and the MAF sensor is calibrated for the stock air box/filter. You're asking for reliability problems messing around with the intake system.

 

+1 on avoiding KN and other oil based filters. The oil used to make the filter work can also get onto the MAF. These cars have very good intake air boxes so you won't see any benefit from a cold air intake. Leave that stuff for your mom's Buick. :-)