CAI (Cold Air intake) requires a tune. I'd personally, and I'm sure many very more knowledgeable members could back me up on this, the best first mod, mite quite honestly be snow tires, if you dont have them and you think you will be driving through snow. Thats safety wise. Performance wise, arguably the best first mod is a COBB AccessPort. I got one a month ago, I'm still in love and can't wait to plug it in and turn a gauge on everytime I get in the car. Not to mention how smooth the power comes through. Do some research on the COBB website on the Accessport and see if its fits your needs.