Round plastic things infront of oil cooler, worth keepign or removing?

[scooby_si]

Just wondered if they actually do anything only i haven\'t currently got one on one side so didnt know whether i should get one or remove other or not bother either way makes sweet FA difference...Thoughts?
Ta
Si

[Fish]

If its the tunnel type thing, then they are worth keeping. They stop the air from bypassing the cooler.

Fish

[scooby_si]

Wasn\'t sure whether it might also prevent a bit of air flow but sounds cunning so time to spend another £48+vat with Mazda
Cheers
Si