Good one, yes, I would definitely recommend this mod, the mesh I used gives a 55% Opening or Air Flow, so you could put a bigger Hole or Diamond and make the opening even larger, IMO would be even better.
It is a bit of a trade off wanting to protect the coolers too.
I have noticed, the odd very small piece of road tar and or bit of leaf attaching to the mesh, but you only have to touch them with a finger and they fall off, so there appears not to be a problem there.
As I said in the other DIY thread anything has to be better than the originals for Summer..
In Winter the OEM's are fine, I definitely would not open them up any more.
IMO when you have 2 Oil coolers their efficiency in cooling your oil is better than you think....BUT!
However, I have always thought that the rear black splash shields and the small slits are air flow restrictive, lets face it if you can't pull the air through the Oil Coolers fast enough they are not going to be efficient in reducing oil temps, and you can have a HUGE front opening like the S2's, but if Hot Air can't escape easily at the back it is pointless..you have to have quick flow through air.