I'm in the process of replacing both LH & RH outer cowls and I'm wondering 2 things.
1.In my pursuit to stop all moisture entering the cabin, particularly through the kick panels, I've come up with the idea of creating a dam at the top of the cowl with a hose in the lower corner to drain away all water that enters through the top vent/grille. Was wondering if anyone with restoration experience can foresee any issue with this little plan?
Which brings me to my next dilemma,

2. At some stage I intend on installing aftermarket aircon and was wondering if any of these systems (I know there are a couple), will interfere with my idea, as I'm unsure whether these systems rely on air drawn from outside or if they run strictly on internal recirculated air? In which case all entries can be permanently sealed and I will not have to go ahead with my little fancy design.

Thanks