How exactly does a lover with a radar phone live? Well, probably poorly if they're fucking someone who thinks a radar phone sounds like a cool piece of technology. You have to feel bad for Def Leppard's girlfriends, who presumably all got radar phones for Christmas back in 1987, when this song was released.
Even for the late '80s, "radar phone" doesn't sound like such a hot piece of technology. Here, Warrant's girlfriends were probably all getting car phones, along with new Trans Ams in which to install them. To make matters worse, when Def Leppard's girlfriends tried to phone their boyfriends to complain about their crappy gifts, instead of connecting the call, the radar phones would just measure how fast Warrant's girlfriends were driving in their new cars.