Depends on if you want to just heat items like corn dogs, burritos, taquitos, bbq, etc. or really cook. I put mine on top of the engine but not directly mounted to a high heat source. Cooking raw brats was fruitless but it warms nicely.
If you really want to cook.. on the downpipe or manifold anywhere else is just heating.
See you on the trail
Couple o' FJ40's, BJ70, UZJ100, TDI