sharkfins can be designed to cover all RF protocols.
one that I'm aware of supports 2 cables for LTE, one for wifi and one for gps. BT is not on the sharkfin, but could be (seems pointless as you need PEPs for beaconing/location stuff).
glad that the m3 doesn't have the ugly sharkfin, but then again, the choices they made were more cosmetic and they did sacrifice reception quality. I often can't get lte to my car when I'm parked (not underground but in a garage that is shared for the apartment complex, not gated and has large window openings). if we did have a proper lte antenna that was centrally roof mounted (giving an ideal ground plane) then we'd have an easier time using the mobile app and turning on the car in the AM, when its cold..
more than half of the time I try to ping my car using the app, it won't get there. could be server issues but likely its lte on my car that is spotty.
while driving, its usually ok, but the point is, the tesla design is a cosmetic compromise. we win on looks but we do suffer a bit on reception, overall. physics is physics, even for elon.