Thanks for the tipo.
These FM radio transmitters CAN work well if you don't encounter radio interference from nearby real radio stations.
I've used these back in the portable CD days, and success or failure depended on what stations were operating on what frequencies. In a large metro area, spectrum space can be pretty full. Finding a vacant space "on the dial" can be essentially impossible.
This does appear to allow significant adjustability of the transmission frequency...to find holes in the radio signals locally. But the transmitter's "power" is the same as the "old days" and is strictly limited to a very tiny signal that won't interfere with radio reception in the car next to you.
I'm not saying this is a bad idea...not at all. I'm saying that these technologies have limitations, especially in urban areas, and especially because as you drive from one radio market to another, you may need to adjust the transmitter's and vehicle radio's frequencies to adapt.
Other options for old school car stereos include "cassette" adapters, and an Aux in...if available. I've been using a cassette adapter in my 2006 Dodge since I bought it. A good one works well and will last for many years.
Again, thanks for the tip.
Jim & Renee
2020 Jayco Jay Feather X-213
previously 2014 Forest River/Rockwood HW 277
2006 Ram 1500 4WD Crew with Firestone Airbags
Every weekend boondocking in the National Forests or at Lake Wellington