-6 teflon lined hose - like Aeroquip's TFE, .320"ID - with appropriate fittings and adapters. Use a cooler with threaded connections. The old rubber hose and hose clamps on barbed fittings are no good and create a huge mess when they blow apart.

I've mounted this stuff under the car, sometimes with a cooler with a small dedicated fan for the really abusive combinations, with good results. Saves all the plumbing and crap at the front of the car.

I've used -5 stuff when using it as connections for 5/16 tubing, but that stuff is oddball. -6 is much easier.