So how about that for an info! Apparently T. Gargour & Fils - synonymous to Mercedes-Benz and currently rebaptized TGF - actually had a Pullman line linking Munich to Beirut. The trip promises to go through 7 lands (Germany (Munich), Slovenia (Ljubljana, Bled), Austria (Vienna), Yugoslavia (Belgrade, Skopje)*, Greece (Kavalla), Turkey (Istanbul, Ankara, Adana), and Lebanon (Beirut)) in eleven days.
*Please note that the ad is undated but that currently Belgrade is in Serbia and Skopje is in Macedonia.
Interestingly some sources say that the line never happened, which apparently is not the case as the line was in effect functioning (interestingly, the German Kaiser Wilhem II actually dreamed of joining Germany with the orient, which makes this line a manifestation of his wishes).
It is to note that the bus in the advertising is the O321H model, which was issued in 1955. This in itself gives the ad a certain baseline date, in addition other sources state the lines were functioning since 1955. Which makes the ad dated to that year by deduction.