Inline thermostat is the way to go, unfortunately I didn't know that when I bought mine! I think the inline must still flow a small amount at all times so you don't get a big pressure drop when it does open the first time, or get a load of cold oil into the engine but it seems to work better. I think you can get higher rated thermostats too, standard is 80c which I have. Also don't get a huge cooler core, 10 row would easily be sufficient on our cars with the small amount of oil they have.