Classic Vanquish engine bay venting.

[Sydney V8V]

On early Vanquish , the square corrugated plate that bolts to front of X member and two front chassis legs has no holes; while Vanquish S has about two dozen vent holes in the plate , and alloy undertray that fits over it has large square hole to let out heat.Here in Sydney OZ we have 8-9 months of year thats between 20 -40c, To rid some of engine heat in early Vanquish , we made holes in engine plate similar to Vanquish S , but in alloy undertray we made louvres instead of a square hole as air travelling under the car will suck out heat from louvres better than a large square hole wont upset aerodynamic air flowing under the car. Hopefully lessening hot air in engine bay while driving and giving the coils maybe a little longer life.

[Sydney V8V]

Hopefully photo of early Vanquish undertray comes out this time; now with louvres to vent engine bay. The Louvres are pressed inwards and towards the front to catch radiator heat travelling back towards it ,leaving the undertray flat below to not upset the air stream.

[DB9VolanteDriver]

I would think that the louvers would work better pressed outwards and facing the back so that low pressure air flowing under the car would extract the heat into the low pressure flow. Maybe it doesn’t matter either way.

[Sydney V8V]

Pressing louvres outside /below the undertray would take away 10mm of ground clearance. Also interferes with air flow underneath the car and may harm aerodynamics at high speed slightly or not at all. We pressed louvres on top like DB9 to catch the hot air flow from radiator and negative air flow below the undertray would suck it out.But we could be dreaming and than again it just looks good when your under the car.

[MichaelV8V]

Have you seen the Harry's Garage review of the Callum Vanquish 25, that has an interesting approach to engine bay venting