Just my thoughts if playing with designing an external filter . . . . .

Having changed many filters that came out sideways on my Buggy like those shown, and having recently been changing the upright ones on my T25 lump, something obvious has been noticed.

My arms are skin colour and not black and oily   

The sideways filter always drops oil as you unscrew it, whereas the upright ones keep it contained

I know its just a silly observation, but one worth noting   

The sideways filter always drops oil as you unscrew it, whereas the upright ones keep it contained

I have had mine on there for 12 years so know how they can drip, I just sling an old rag on the ground or undo it over an old washing up bowl

Thats fine 

Mmmmmmmmmm under stand our conversation about rear view stuff now

Its when I am all packed up and going somewhere, cant see much out the back, the latest rear view mirrors with a feed to a tiny camera are quite neat I think....

https://www.youtube.com/watch?v=mWSMdgifvls