Take a look at the Beetle's license plate. D 810 is the number of Franz Schubert's string quartet in d-flat, titled Death and the Maiden.

Also, please be aware of the fact that at the time I drew this comic, I did not have a driver's license. And by that I mean: I had effectively never sat behind the steering wheel of a vehicle, and the few times I had been (passively) driven along some highway, I hadn't given much attention to it. I'm your typical city slicker, and the city I've lived in for 40 years has excellent public transport. So, no need for driving a car or even show the slightest interest in it.

Why am I telling you all this? Because I do own a driver's license by now, I'm spending half of my days on the highway, and it makes me cringe to see how blatantly wrong I've drawn them back then! Not only does the driving jump from the right side of the road to the left and back every few panels, the road markings look like out of Grimm's Fairy Tales, and don't get me started on the 'design' of the cars.
Yet, I still can't draw cars, so that one remains a constant.