Kamei front spoiler vent holes

[Wally]

Hello,

After it lying for about 5 years in my basement, I finally dusted my NOS Kamei 1302/03 front spoiler off and want to mount it.

However, I have the oil cooler right behind the slotted front valance and the spoiler will block the air for the oil cooler...
What would be the best way to perforate this ABS-made (its a ductile plastic sort) spoiler? Holes?round, elongated? Slots? Big open rectangular hole?

Residual strength is of course a major concern for this.

Here are some pics of it:







Thanks,
Walter