This looks discouraging...

30 seconds with a cordless grinder and cutting disc and she is gone galloping over the horizon.

but it’s the thought that counts :)

GPS tracker with backup battery is about 98 % reliable . Until a thief comes with a GPS jammer and cell phone blocker.

both of those jammers are available from China and you can be sure if WW 3 breaks out there will be chinese PLA agents all over the country with a couple of those stashed under the bed awaiting instructions to switch them on at the appointed time

I have never had my car stolen. I attribute this to two factors:

• I drive the ugliest car in town. I can park my car in downtown Laurence, MA at nite with the keys in the ignition, and I will be sure that it will still be there in the morning.
• I always park next to the most expensive car in the parking lot.

I am sure the half a hoagie rotting on passenger seat and empty bear cans carefully arranged to make your performance car look derelict is an effective deterrent to being selected for the "where did my car go" club.

What you park next to likely has little effect, but I guess it is fun to park so close, such the owner has to take extreme care to not get any of your car on his upon departure.

A rattle-can paint job will add a nice patina; as well as make a statement.

On the more serious side:

Older cars ( traditional American, with mechanical distributor, points and condenser ) can be ever-so-easily modified with an ignition kill device to ground the coil. A locking hood adaptation or shielding if factory cable released, will also be very effective.

Instead of one nice car, buy like 5 shitty cars. That way, even if it gets towed away, you won't care.

Sell it before it is taken!