Iggy, On the back wheels it was easy to screw the flow thru sensors on the existing valve stem extensions (though I am still debating whether to change out the inner flexible steel braided extensions to solid steel extensions).
The problem on the front wheels is that the position of the valve stem (no extensions on the front valve stems) and the opening in the wheel cover is such that there is no room to screw on the extension without removing the cover. With the wheel cover removed, the extension will screw on but then there is not quite enough clearance to fit the cover back on. I am currently debating whether to get a short 45 degree extension which would put the sensor outside of the opening, or just enlarging the opening in the wheel cover about half an inch to provide enough clearance without an extension.
I don't know but this might only be an issue with 19.5 inch wheels.
Wayne & Pat
2014 Georgetown 328TS
2013 Chevy Sonic Hatchback