The Car Phone mounted in the Mercedes-Benz 350SL is a Sonab 4145 NMT which was introduced to the market in 1981, two years after the scene is set to. The NMT system itself was not active in Norway until late 1981.
A child is watching a popular Norwegian program for children called "Så rart" on TV. The program is aired on NRK, which was the only TV-channel in Norway back in 1979. You can clearly see the NRK-logo in the corner of the program. However, NRK didn't use logo in the corner of the TV until the 1990's.