I could be wrong but I thought my thermostat on my oil cooler from GTM is always letting flow through but when its cold in the winter (OP lives in northern IN) it will switch off. that's why I got one on mine. You do not want the oil too cold when hard driving it and could if you didn't have a thermostat on.

 

Just pull the hood latch inside the car and leave the hood as it is. It'll be like a special air intake