Understood.
A standard Stop Lock through the steering wheel will crack the windscreen when forced upwards. Clamping it sideways towards the gear lever/floor prevents it being used to mash the windscreen, but you will have to check it will fit like that.
I used to own an Austin Montego - a car with zero useful security. The door locks and ignition were easily shifted with a screwdriver making it impossible to properly secure. I had a Stop Lock (which broke the screen) but the most important was a cheap alarm positioned INSIDE the cabin. When that was sounding, the decibels made it impossible to sit inside the car.
You can get a cheap car alarm for £20. Put the siren (or sirens) under a seat(s). Make sure you have ear plugs so you can silence it when needed.
Here's an example
https://www.ebay.co.uk/itm/Car-Secu...779521?hash=item1ce75df801:g:80kAAOSwOJVeh0nV
It's from Singapore but will be Chinese made.
Also consider a flashing LED on the dash and a hidden switch to interrupt the starter motor circuit.
PS On the Montego I fitted stainless plates inside all door panels. These were 1.5mm sheet material positioned to stop the door panel being drilled to use a wire to pull the door lock mechanism. The Panda door is stronger with side impact beams so I don't know if this is possible on our cars. Heavy duty double sided tape will stick the steel plates inside the door.
The Monty had weak door locks. The passenger lock was removed and the hole covered with a chrome cap. The driver's side had a stainless escutcheon around the lock hole. That prevented it being turned with a screwdriver. Stainless is tough so it was fiddly to make but could be laser cut.
These wont prevent the windows being broken, but glass is more easily replaced.
Screws like this will retain a door escutcheon plate
https://www.ebay.co.uk/itm/M5-M6-M8...hash=item214b12ce40:m:mTUxzUQhPdurmzNUsfViItg