Anyone who has a Small Car plastic oil dipstick knows they can be fiddly,
but it is nice to be able to check the oil level without having to move
everything out of the rear hatch area just to get to the stock dipstick.
But that plastic tube is a major PITA!

There are two oil level rings marked on the plastic tube. You definitely
want to add oil when the oil is at the low level mark. Trying to check
oil and get that tube back in, I managed to break that tube right at the
lower ring. That is a weak spot. Turned out to be good fortune. I put it in
the oil tube and it went in easily. No more fiddly. As long as there was
oil  anywhere in that plastic tube up to the top mark I was good. IF oil
didn't show, add oil until it showed up the tube again. If oil just barely
showed, it would take one quart.

That little adjustment made having a Small Cars oil tube worth it.