"Actually they did and still do. Car radios have always had a pre-amp in them. Fractal antenna's are a lot more complex than just repeating patterns, I have built some for TV's. The ones I built for TV reception did not pick up LVHF but that was only because they weren't designed for that. LVHF requires larger elements than the ones I made, but for HVHF and UHF, they were fantastic and did not require a preamp as my more conventional antenna's had."
Generally speaking, the closer the pre-amp is to the antenna, the better job it does. That's why Subaru put it about 6" from the window antenna, so it would work with the inferior antenna. Now if you have the old style antenna, then the pre-amp can be far from the antenna, even inside the radio, since the old style antenna gets a stronger signal.
I forget where the FM band is. Is it between the tv channels 6 and 7? I remember back in the day you could tune in channel 6 TV on many FM radios and some radio stations you could get with old TV's that had fine tuning after turning the clunkity clunk tuner. Anyway FM is in or close to Low VHF, requiring larger antenna. Especially down at 88.5 where my favorite station is.