thats just my experience on a new dodge with oem bluetooth and beats audio, wanted to test fm transmitter there to compare audio and didn't notice difference. bluetooth is not an audiophile method of listening to music so i wasnt expecting vinyl quality.
With a strong signal FM actually provides great quality.
Try it out it's 25 on Amazon with a great return policy
I came from a cassette adapter then an fm transmitter. I'm using a bt45 now, no comparison.
Now MAYBE if you live in a rural area it'll be good, but not in Houston, I'll tell you that much.