A piece of fiberglass cloth and some Epoxy Resin and lay it up on the backside of the tear. It will be out of sight and stronger than original. Some fiberglass resins will not adhere or cure to some plastics but Epoxy usually adheres better.
I've repaired many damaged aircraft plastic instrument panel overlays using this technique.
Wear some Nitrite gloves to keep the epoxy off your skin. It's a bitch to try to get off later.
Cut piece of fiberglass cloth enough to cover and extend past the damaged area on the back side. Clean the area totally. Brush the epoxy on the backside of the damaged area
then apply the cloth over the wet epoxy. Then use a disposable brush to wet the cloth totally. You may want to lay up a second piece of cloth over the first before the epoxy dries. f you use the epoxy linked below you will only have about 20 minutes before it starts to set up and harden.
https://www.amazon.com/Bondo-20128-Fibe ... B002JRGOT8
https://www.amazon.com/Pacer-Technology ... B0084UAPMG