Question: Which way does the rod face ?
If the tip faces forward at speed it tends to swing in the wind especially when overtaking or passing lorries / buses. To stop this if you use a bit of string the rod bends at speed.
if the tip faces out the back there is the worry that someone will run into the sticking out bit.
I have got over the problems by using the front bar and by manufactoring a small bar which fits into where the engine compartment opens. This is now good for a steady 90 miles per hour.