I install my RFID inside the front windscreen using transparent roadtax sticker. It works without any issue. Lastly my RFID is removeable.

I cut half the size of the transparent road tax sticker. The RFID is stick on to the road sticker.

more importantly is cheaper than buying RFID holder from shopee and tends to fall when is way too hot under the sun.

the best part, the RFID probably will last way longer than sticking outside.