Performance parts for a 2007 saab 9-3 sports sedan???

hello, i was considering tunning my car a bit and i was thinking of puting a blow off valveGreddy style), a performance chip ( stage 3 surge o2 chip combo) and does it make a difference if i put in a air intake if so what kind, and if you have any other suggestions as to what would be a good idea let me know, MY MAIN CONSERN was the warrenty i just got the car like 2months ago new and i dont want somthing to get ****** up and then find out the warenty wont pay for it because i "tampered with the engine" well anyways thank you