The colder air will improve results with a true CAI, not to knock your own intake. Just with the NW CAI setup the airflow itself improved results. Now the colder air improved results not by what your thinking, but because of the colder air the DA was probably better. Now the colder air is loved by our cars but you have to be able to suck it in. Hot air and cold air relative to DA definately makes a difference and you should see a significant increase in power in better air. Mine is almost a full second differential between summer and winter. Now just taking off my grill so my NW CAI can breathe a little better increasing my car by a tenth.
Yes get slicks and then we can fairly compare numbers. Also get familiar with getting accurate DA readings when you make good runs. That way if your off by a tenth or more in different passes with the same temps reading on your dash, you can pinpoint it to differences in humidity, barometric pressure, etc. It's easier to say something went wrong, but when it comes down to tenths or thousandths, it simply can be the weather. When you are ready to take the next step, look up a Performaire PA2 from www.biondoracing.com. Most of all have fun and be safe.