Nothing wireless is secure, especially when dealing with end user electronics.

The only possible exception is WiFi and commercial wifi services like 4G/5G… In the case of WiFi, it really depends on the configuration. A local ISP was, by default, programming their combination router modems for WEP security for years after it was known to be insecure, and for years after tools to obtain the security key for WEP were commonly available. However, WPA2 and now WPA3 is used by corporations to secure their wireless traffic, and those technologies have been made available to the public on almost all consumer WiFi products made in the last few years, though, some may need to be updated to show the option for it. As far as I know, as of now, WPA3 has no known vulnerabilities that will allow a hacker to penetrate into the subject network. The weakest part of the system is people using poor passwords for their wifi, which can be easily guessed, which is not a fault of the technology itself.

IMO, the best, most shining example of well implemented security is PKI, which is used in HTTPS/TLS. A high security asymmetric key is used to generate a short-term use symmetrical key to secure the communication. It becomes basically pointless to try to break the encryption at that point.

But this isn’t the issue in the OP. The problem is: where does everyone keep their keys? If you said “at the front door” you’d be right. In most cases, keys are at, or very near the front door. Where are most people’s driveways? At the front of their house, next to the front door. There’s usually enough distance to keep the fob from being detected by the car and unlocking it for anyone who walks up, but with a small amount of tech, attackers can pull the signal through your front door and relay it to the car. The process is actually kind of trivial. This is known very aptly as a relay attack. One attacker with a high gain antenna loop, places that loop on or near your front door, while their partner has another device which is relaying the signals from the high gain antenna to the car. This makes the car think the key fob is nearby, and it unlocks the doors, and the vehicle can be started.

Once started, the vehicle will not automatically power off if the fob goes out of range, since that would create an unpredictable safety hazard. At this point the attackers only job is to get the vehicle somewhere that they can work on it for an unlimited amount of time, and program new fobs for it (which can be done with diagnostic tools).

The best way to prevent this is simply not to keep your keys in range of your front door, nullifying the attack. Otherwise, buy an RF blocking key box to put them in at the front door. Something that automatically closes would be beneficial here; something with a Faraday style mesh, or lead (embedded in the walls of the box) would be best IMO. Keep any spare keys in a similar lock box elsewhere in the home.

My family has our keys, at least 10 feet away from the door for storage, in our kitchen. It’s a short walk from the door down a tiled hallway, which makes for easy cleanup if someone walks over to get their keys from that location with muddy/wet boots or something.

Relay attacks are very common and easy to execute with a high degree of success. To their credit, manufacturers have done their diligence in implementing anti-replay attacks (where an attacker well record the signal to unlock/start a vehicle, then replay it later for access), but the relay issue is harder to account for. From the perspective of the car, or simply looks like you started the car, dropped your fob on the ground and drove away. This is a legitimate scenario, and one that is entirely plausible for an end user to create unintentionally.