Let's take a perfectly good, classic sports car like a 1987 Lotus Excel SE.

There's plenty of room for the blower.

But how to make the bonnet bulge?

If we lived in eternal-sun like California, I'd leave it
but the rain in New Zealand can be severe.

The first draft shape, and omigod, it's so tall - to clear the pulley

This shape looks reasonable

I don't know where I am going with this now, but it was a friend's idea
and so far it looks good.

Some ply on the sides and a top

The louvres will not be open to the rain
This backing plate is glueing and the bottom
louvre is also glueing into place

-- and you would never know it's not sucking air and rain

But this is looking far too bulky.

Bring out the skilsaw and grinder:

Fill in the louvres:

It's just okay-- how about extending the side pieces?

And filling in the gap?

Ok, it's now a lot tamer

Back..... Or here for the final result