The back seat of a volkswagen is almost a synonym for uncomfortable. This is referring specifically to a VW beetle, and perhaps the jetta too. These are extremely small cars, without adequate room in the back for lovers.
Not all volkswagen's are that uncomfortable though.
My girlfriend owns a VW bus, which has a couch in the back, which flattens out into a good-sized bed.
Plus the VW bus also has shades for all the windows...

So, in conclusion, the back seat of some volkswagens are quite ideal.