[Showdown]

That's the trombone cooler that is hidden with the G-body bumper. Best advice would be to remove that and replace it with a carrera cooler (with or without fan) that you can tuck up into the wheel well. That said, it might be really tight or impossible if you're keeping the battery box there. If you're not using the dual batteries then removing the battery box is probably the best approach as it'll free up a lot of space.

An alternative is to get any oil cooler- even a smaller one that fits and stuff it up there. I'm sure that CSF makes something that will fit.

And for the cheapest solution, I guess you could just cut down the trombone to make it fit... You'll have to braze some fittings on but that's not terribly difficult and won't cost much at all.