wow, mate thats a excellent job for only a few hours.
once i get some spare cash im defo going to do this. but im also wanting to extend the tray further up towards the back and possibly go the whole way.
this should massive improve the airdynamic flow, give better grip and hopefully a increase in MPG.
I have looked into the possibility of a full under floor plate. My father in law is a technical architect with years of experience in autocad design so plans from photo's of the under floor and basic measurements he can use a measuring utility on a photo to get the exact length etc. Then he converts it over to dwg format.
First thing before even considering a complete cover is to make sure the current floor pan is in perfect condition without the merest hint of rust... Then a thorough under seal.
Aerodynamics can be factored in with a mild but effective venturi effect, following the corrugated effect of the original floor with right angle 40mm drop then 40mm width corrugated square peaks and troughs down the length of the floor pan.
Now the clever stuff... Before cutting out the three panel widths, you slightly angle the bent in ridges so they are wider at the front and narrower at the rear of the floor. Like a fan effect but not as noticeable to the naked eye... This will give the mild venturi effect by speeding up the air between the ridges as it travels, increasing speed of the air as it goes further along the narrower ridges.
Three panels in all... One for each side floor pan and leaving a natural exhaust clearance tunnel and one panel following the venturi effect of the other two but starting after the rear suspension and termination at the rear bumper valence. The ridges being increased in drop towards the bottom of the bumper.
The front of the two floor pan covers need to be slightly angled upwards if the bulk head and rear of the front wheel arch to protect against snow, stones and mud getting in between the current floor and the new covers.
Same again for the front of the rear panel...
So. How to fix them into position?
Quite easy really, especially on a Lusso model without the plastic sills.
The floor protector can be extended to beyond the sill bead and cover the bottom sills too. It can be bent to fit the bead of the sill for a tight fit and then drilled and bolted through the bead
The peaks and troughs also provide excellent purchase for Zeb inserts to be used which use oblong alloy blocks to clamp against their walls and so no nut showing to rot away.
Unfortunately this means drilling and bolting through the current floor downwards from inside to out though.
Finally attached to the exhaust heat shield area.
The rear panel can be done the same way through the drain holes already there.
Good idea, I think so... Is it legal as far as road use?
Yes, but needs an MOT IVA inspection certificate of road worthiness for safety and security of the work to kit car standards. Then you just present that certificate when the car is due an mot.. or you will receive an advisory notice every time...
Like I said... I have considered it