Our car experts choose every product we feature. We may earn money from the links on this page.
Whether it has a tape deck, aux input, CD changer, or none of that, there's a way to make wireless music work.
When it comes to used cars, I'm pretty open-minded. In the past four years, I've owned a Lincoln Town Car, Toyota 4Runner, Mazda 3, Mazda Miata, Acura CL Type-S, Lexus LS400, Honda S2000, and Porsche Boxster. I'm currently considering Toyota Centuries, BMW M3s, and Chevy Corvettes. No make or model is a dealbreaker. The only thing any car absolutely has to have is a way to play music directly from my phone.
Considering my 2006 Lincoln is the newest car I've ever owned, I've never had a car with Bluetooth or even an aux port from the factory. But in almost every used car, there's a way to make Bluetooth connectivity work. It just depends on what era your car comes from, how much you care about audio quality, and what your budget is. Regardless, these are the best ways to do it, listed in order of my own personal preference.
This is the easiest way to get consistent, reliable, hassle-free Bluetooth with very little investment. Especially if you own a car that's too new for a tape deck but too old for a factory 3.5-mm auxiliary input, this might be your key.
Because long before radios had aux inputs on the front, they had extra "auxiliary" inputs in the back. A result of radio-sharing between different models with different equipment, these aux ports are usually just unused ports with a proprietary connector. Sometimes, your CD changer may be plugged in there, but often it's completely unused. That was the case in my Porsche Boxster.
Googling "[your car model + year] + Aux input" should get you info on whether or not this is an option. For many single-DIN radios, you can also search specifically for the unit's name. My car, for instance, has a Becker CDR-220 that's shared with other brands. Searching for that brought me to DiscountCarStereo, a site that has both aux input adapters and Bluetooth receivers for every conceivable stereo setup. This isn't sponsored or part of an affiliate program, I just use them every time and usually get good results. That being said, if there are multiple options, pick the more expensive one. Some of the stuff on the site can be cheap and low-quality.
You may also need specific keys or tools to remove the radio. Order those alongside your Bluetooth to aux adapter. If you're comfortable with splicing wires, also make sure to get a Ground Loop Isolator/Noise Suppression Filter. That prevents background whine from electrical interference, which can get extraordinarily annoying at high volumes. I tried to get by without one in the Boxster and the faint whine of interference is a constant reminder that I'm an idiot.
Once you have everything, you can use the detailed instructions from Discount Car Stereo. But the basic steps are the same: Remove the headunit, connect the Bluetooth receiver, wire in the loop isolator, program the radio to enable its aux input, and you're done. You usually can't use the skip or rewind function without a lot of extra work, but you should have high-quality Bluetooth audio streamed directly to your car's speakers without disturbing the factory look of the radio.
If your car has a standard single- or double-DIN-sized radio, you can't beat the functionality of a modern headunit. With a harness and installation from Best Buy, you can get full Bluetooth functionality, internet radio, or even Apple CarPlay and Android Auto.
The downside is that many of them will look out of place. Far too many aftermarket radios are stuck in early-2000s era design, with flashy lights and chromed buttons. With enough research, though, you can find a radio that fits the style of your car. If I had a Nineties German car, for instance, I'd go with a the VDO Continental TR7412UB-OR. Again, not an ad, just something I saw in an E36 I checked out that looked sweet.
If you've owned your fare share of old cars, you should be familiar with the old tape-deck-to-aux converter. Through wizardry I won't even pretend to understand, you can plug your phone directly into a cassette tape that somehow makes Call Me Maybe readable to a 1993 Lexus. The quality is low, they break all of the time, and they can be finicky when the wire gets in the way, but they work.
If you want them to work wirelessly, expect much more rigamarole. Bluetooth cassettes exist, but they run on batteries. Since the casette has no idea whether the car is on or off, you also have to remember to take it out and turn it off every time you get out of the car. For long drives, expect to stop the music and charge the battery every eight hours or so. In the long term, the battery will wear out and you'll need to replace it.
It's a point of personal preference, but I'd typically recommend skipping the wireless version and getting the tried-and-true aux version. Yes, that will require a headphone adapter for most modern phones, but it's better than having another gadget to charge.
There are cars that have no aux port, no tape deck, and no easily swappable headunit. Sometimes, you want a solution that you can use in multiple cars, too. For those situations, there is the FM transmitter.
An FM transmitter connects to your phone via Bluetooth and broadcasts the audio output on FM radio bands. That can be picked up by your car's normal factory radio, which seems to solve the issue.
In reality, they're far more frustrating. You have to find an FM radio frequency that isn't being used, which can be tricky in crowded cities. Even unused ones will likely have some interference, degrading audio quality. Go on a long trip and you'll pass through dozens of radio stations, often requiring you to scan through tons of static to find a free frequency. It's not graceful or permanent or particularly high quality, but if nothing else works it probably will.