Not arguing either, Maybe were talking around what I am saying a vent tube. One side (facing driver) has a small hole by the front end on the side top part that has a PLUG in it. Small tiny plastic plug. That is transferred from old to new battery. Passenger side on the top side part, there is another small hole for the cell bank on that side. That is where a L shaped push in plug goes, and then a small tube runs down the side to a hole in the bottom. Between the bottom fo the batt tray, there is about a 3" gap before the venting outside the vehicle.

Aston1936 on YouTube shows this exactly. Like most Astons, whenever a previous batt was replaced the tube no longer is even in any of the holes. (take or cut a 6" piece of straight coat hanger, put in tube and align before dropping batt all the way in. Then reach under vehicle, and pull hanger out. Easiest way.

1. Resetting seats, windows ------ not hard just push button till you hear a click, then the other way till a click. Seats-- just move all the way to each position.
2. ARE the coast down mis-fire procedures ONLY on DB9's????? I dont know, but i suspect they are.

A> 70mph-30mph at least 5x times if not 7x times in a row WITHOUT touching the brake. So up to 70, then coast down, then back up and then down etc.... I figured you need about 10mi of highway at after midnight to do this. Running 30mph on highway sucks. If you touch your brakes, then you have to start ALL 5 or 7 over again.

I think the way around the coast down ------IS keep you battery maintainer plugged into the cigarette lighter plug in the trunk. Taking extreme care not to touch positive lead with any metal. (take 4 short socks, and put over positive lead when removed) Remember always take negative lead off first and put on first. I think this retains all of the functions for mis-fire, windows, and seats. Might save alot of time and effort if it does. I did this, due to not being able to do the coast down procedure anytime soon.