I found your videos on Utube before this here. I think they are very informative, Thank you for sharing. I do have to do a lot of sifting and jumping around for a newb like me. I look forward to seeing a step by step of first things first, " ...After you have all your gear in....etc". Do this, then this, then this, and that.

Something I can follow would be a blessing. None the less this is surely something to add in to other videos to get me started from top to bottom.
Some are doing it while in the car, others NOT in the car...etc.
Also, I have seen people take RTA readings with the zero axis head on narrow angle of the mic, and I seen your ear to ear 90 degree version, and then yet I have heard to take readings of the tweeters in dash from opposite sides of the car for better results.

(left tweeter, right passenger window/right tweeter, driver window). etc...

Does it make a difference? Why?, and how? and is there a measurable better method?