Front blend door heater core question

I'm finally going to tackle both sets of blend doors and had a question about the one accessed from the frunk. In every video I've watched, the car is simply re-assembled - nobody talks about bleeding the system since it's been exposed to air. Don't you at least need to open the purge valve or is the amount so insignificant that is doesn't matter? Thanks.

I wondered the same thing and decided to use the method where you take out the radio and go in that way. I had access to both panels, including the one that is bent in the middle. That bent panel makes it seem like three panels.

Quotes source post: 20186552

I wondered that myself. I saw something that said there were three panels, but I thought that 2nd panel in the dash was the same one, but this is the first time I've seen anyone mention that. I was going to go in the front as well as part of phase 2 and add buttons for the spoiler switch and my garage door opener while i had the horseshoe off. I got some 3D printed plugs off eBay was was going to use those with some RTV. Did you cut the plenum with a knife or use something else like a multitool?

I used a boxcutter with a brand new blade. The duct material is surprisingly thin, so it cut very easily. I braced my hand against the metal frame of the dash to help with my accuracy and speed. You could easily get slicing too fast and slice where you don't want to slice if you are not careful. Just take it slow. What year do you have? The trickiest thing for me was learning/understanding how to release the clips to unlock the air vents on my 2004. Different years have different designs.

In case you have a 2004, here is a cut and paste I wrote to another member which might help avoid some frustration: Since I just did this fix two days ago on my cabriolet, I wanted to pass along the one stumbling block I had with my 2004 and thus the updated interior, just in case you have the newer interior. Once I had the stereo out and the four screws for the frame out, to get the two-air-vent-cluster out, I had to stick two ice picks into two silver tabs and pull them down to release the cluster. Each of the tabs is located in the center of a vent, in the "roof" of the vent. Use a flashlight through the vent and you will see them. When both tabs are pulled down, the vent cluster just slides out. I saw lots of boxster tutorials but they don't have to do this procedure. The few dedicated 996 fix videos never covered this step. Sorry if this doesn't apply to you or if you found videos that actually covered this, but it took me an extra hour to figure it out so I wanted to warn you.

I've got an 02, so it might be different - but as with other things on this car, I've come to expect anything. Thanks for the heads up though - you never know.