Any reason not to put your tefilin inside your car's spare tire when driving?

Question

For cars that store their spare tire in a well inside the trunk, that seems like a good place to put my tefilin while driving -- it takes up no extra space (if they fit in the middle of the tire), keeps them from rolling around, keeps them covered (of course you risk forgetting them there!).

Assuming they're not getting dirty or greasy -- any reason (practical or halachic) not to do so? Yes they might end up smelling rubbery ...

Answer 1

Be very careful that you don't forget them back there, especially on a hot day. I know from unfortunate experience that prolonged storage in a hot car is very detrimental to the health of the straps, at least.