Any chance that the "smell" could be the result of oil or antifreeze "leakage" getting on the exhaust/manifold during your "spirited" uphill runs? I would check the antifreeze reservoir since it is SO close to the exhaust, ie, leakage. Also, check to make sure that you have sufficent "fluid" in the transmission since it is "taking" a beating with going uphill @ a good pace!