Just another quick(ish) question inspired by another post earlier today. The original question asked what fixing to attach a splitter with, and one of the responses was a flat head allen bolt. The response was perfectly fine, but my experiences of tintop fixings suggest allen bolts are not that good when subjected to the underside of the car. The ones I've had to remove after many years of use turn to mush when an allen key is used.

So my question is has anyone made a choice of fixing based on where it is on the car, not just what IVA asks? So to continue with the example, I would maybe look at torx rather than Allen, or even standard six sided fixings that I can get a socket wrench on to. (Although the latter would defy the point of a flat fixing on a splitter)

I suspect by the time I get to this point, my 'locost' budget will mean I use whatever fixing I can get my hands on, but in an ideal world is it something that is considered by builders?

Or am I looking at the wrong side of 'an ounce of prevention rather than a pound of cure' IE I should be looking at preserving the fixing rather than compensating for the level of corrosion it will produce?

1 word, stainless :-)

Well, 5 words maybe, stainless, with some copper grease