Other mistake: Mugged: When Arnold gets mugged, some of the shots use a flipped background. Note the wall colours, and the sign that says "MARKET," which is reversed. (00:01:16)
Other mistake: Mugged: When the people are standing outside Sunset Arms waiting for Arnold to come out of the garage, Oskar is coloured incorrectly: he has grey hair, a grey beard, an orange shirt, a light blue jacket, and white shoes. (00:05:12)
Continuity mistake: Mugged: Throughout the scene with Arnold and Grandma on the bus, Arnold is not wearing his hat. When the creep runs off the bus and the camera shows Arnold and Grandma from outside the bus, Arnold is wearing his hat. (00:11:35)
Answer: The show is based in present day times. Plus most cars aren't old fashtioned, I recall seeing a limo and not to mention a cherry picker, etc.