On Lexus, I can personally say that the warning noises do seem inadequate. I was once in a rush and on the phone, leaving the car running when I came to a stop to transfer from the cars Bluetooth to the handset. Since my sequence of events was different, I forgot to turn the car off before exiting. I only realized there was a problem when I went to lock the car and didn't get the lock confirmation beeps. However, the locking error beep was on the gentle side and not that different from the confirmation beep.
My recollection when opening the door to leave the car with the engine running was that there was no audible warning at all or that it was not very prominent. In a garage, you might not lock the door at all so are relying on the first warning only. On the other hand, a car running in a garage is more noticeable than out in the open.
On my Mercedes, the warning is definitely visual. My recollection is that the audible part is again not that prominent (I need to check), but again, I have exited and only realized my mistake when trying to lock the car. I've never made the error when stopping inside the garage as in the garage it just seems more obvious that a car is running compared to not running. The locking error noise on my Mercedes is pretty noticeable and not as gentle as Lexus.
My recollection when opening the door to leave the car with the engine running was that there was no audible warning at all or that it was not very prominent. In a garage, you might not lock the door at all so are relying on the first warning only. On the other hand, a car running in a garage is more noticeable than out in the open.
On my Mercedes, the warning is definitely visual. My recollection is that the audible part is again not that prominent (I need to check), but again, I have exited and only realized my mistake when trying to lock the car. I've never made the error when stopping inside the garage as in the garage it just seems more obvious that a car is running compared to not running. The locking error noise on my Mercedes is pretty noticeable and not as gentle as Lexus.