I've finally been able to add a true cold air set up and get the air filter completely out of the engine compartment.

After moving the battery to the trunk, I used the space to route my cold air tube there and then mount my air filter directly underneath it.

As it stands, I'm running about 25-30° over ambient since there are still paths for hot engine compartment air to reach the filter. But it's about a 40-50° reduction from where I was. No change to the calibration so far but there's a marked improvement in power and throttle response. The 4" diameter tube seems to have counteracted the increased length (I was hoping I wouldn't suffer from excessive pressure drop).

Next step is to get a lower profile air filter, built a box around it and then probably route a tube facing forward (possibly cut a hole in the front air dam).

After that, I'll start addressing the MAT table to see how I can take advantage of this...