I'm going by the BMW E90 (Top HiFi option) which has 3 physical FM antennas FM1, FM2 and FM3, all in the rear glass, and a fourth "FM4" which is not a physical antenna but a combination of FM1 and FM2.
They really didn't want you losing signal!
This isn't even mentioning the festoon of other antennas for DAB, mobile (which has a backup too and phones home in a crash: in case the shark fin is broken in a crash)
I could be wrong, but E90 with the best HiFi package is a very rare exception to the rule. I wouldn’t say you often see such configurations.
It’s cool they did that but it’s almost like they are trying to prove some point — maybe to be the best in the market for FM by a hair. :) One antenna is more common than 3 to my knowledge, by far.
Fair enough, I just happened to have an E92 and one day I read all about its systems when it had some major electrical issues :) (Turned out they were due to someone forgetting to clip a piece of harness back in place after some work, and as a result the harness rubbed against something in a wheel arch, eroding the insulation and letting water in intermittently screwing up the CAN bus!)
They really didn't want you losing signal!
This isn't even mentioning the festoon of other antennas for DAB, mobile (which has a backup too and phones home in a crash: in case the shark fin is broken in a crash)