I believe I am the only Contour running an oil cooler.
I use a B&M oil cooler meant for the Integra.
Its a stack plate design.
Its small and mounts easily in front of the radaitor in he front bumber opening.
If you use an oil cooler, you need a t-stat (recomend one built into the sandwich adapter).
Make sure that which ever oil cooler you choose has atleast 1/2" ID fittings/hoses, some use 3/8" and that is to small.
There is plenty of room for the stock oil filter, so thats not a concern.
The hard part is routing the oil lines safely and without too many bends.
I am in the process of designing an oil cooler that won't require airflow, and can be mounted next to the filter.
As stated, the oil cooler isn't really needed for a daily driver as the effects of cooler oil won't be seen.
But cooler oil is always beter.