It’s been years since i’ve done this. It’s been years since I turned on my car radio. The local stations don’t really interest me but the stereo has a CD player. Will it play an MP3 file?
Most modern CD players will, and most will have the letters “MP3” somewhere on the front face if they can.
Seeing as CDs are cheap, why not try?
Worst case: you can’t play MP3s, but you can burn it as a regular music CD
What format is regular? wma?
Definitely not; regular CDs are Red Book format carrying 16-bit PCM audio at 44.1 kHz. Just start with (preferably) uncompressed audio of at least that quality (so typically FLAC, WAV, though there are many options) and let the burnerator program do its magic.
Note: you can only get 74 minutes or so on a normal CD
To maybe clear things up a bit, there are two basic types of CDs. The first is a conventional audio CD, formatted like any other commercial audio CD. You can burn these with your own music with various programs, such as Windows Media Player. You can only fit 74 minutes of audio on them, but they’ll play any file format (MP3, WMA, whatever) that your computer can decode. And they’ll play on pretty much any CD player ever made (though some have trouble reading some kinds of burned discs).
The other is a data disk, the same as any computer CD. These can store any file format you want, including MP3. Some audio CD players will correctly recognize these as data discs, and be able to interpret some file formats (MP3 is popular). If it works with your drive, this may be the better solution since you can store 10+ albums worth on a single disc (since the files are stored as compressed MP3 instead of uncompressed). As @scudsucker says, the drive may have “MP3” printed on it somewhere. If so, you can just dump a bunch of MP3 files in the root of the data disc and the player should be able to see them. More advanced players may support file folders and playlists.
Many modern sound systems support USB drives. Just dump a bunch of MP3 files on a thumbdrive and plug it in. These are always data drives and will always support MP3 at the least, and probably a few other formats. If your drive has a USB port, give this a shot.
Note too that there are different versions of MP3. Generally speaking MP3 is a lossy format (lossy = crappy). However 320 k/bit (bit rate) & higher are acceptable. Anything lower and some of the music is being dropped. This happens to facilitate a smaller file size. This won’t matter if you have a crappy sound system but if you have a decent sound system you won’t be taking full advantage of it using MP3 files.
The most common lossless file is FLAC. As to be expected however, the file size will be much larger - as opposed to MP3, it’s storing all the information available.
Sadly, the advent of storing music on cell phones brought about a drop in the quality of the sound that we hear.
OP here. To clear some stuff up, I have 47 virgin CD-Rs on the shelf under a layer of dust. I burned 7 mp3 songs or so on to #48 and will give it a try today. The car stereo has no USB port. It does have a 3.5mm mini stereo jack but I don’t want to dig up the retired iPod and reinstall iTunes. And I have those unused CD-Rs.
You just need a CD burner program that can import MP3 files, or else some conversion program that puts them into the correct format for CDs. I have never heard of a CD drive that can play MP3 files directly, but there are dozens of programs that can play MP3 files on your computer.
This makes me wonder how easy it is to find CD-R blanks nowadays. It’s probably been 15 years since I bothered to. If that’s an “audio in” jack, you can use the headphone jack of your phone to feed the music from your phone into the car. (Or Tuned-In Radio, audiobooks, podcasts, or whatever) If you have a new iPhone without the headphone jack, there’s a lightning-to-headphones adapter also. If your phone is so new it doesn’t even have a lightning port - well, there’s always AM Radio top 40.
Last time I checked years ago, most music software for computers - Windows Media Player or iTunes - would also write CD music discs.
AS scudsucker said, many modern CD players can play MP3 files directly.
OP: Most CD-burning software gives you the option of burning either a “music CD” (or “audio CD”) or a “data CD.”
OP here: Mine did ask and I selected “audio”. I’m heading out in about 11 minutes and I’ll see if it plays then.
There are many free CD Burner software available. Google ‘free CD Burner’ or similar such thing.
Typically one just drags music files to the CD software. The CD software will automatically convert the original file type (ie: FLAC; MP3; WMA etc) to CD format, playable on any CD player. I use the free version of AShampoo. Not saying it’s the best but it works for me.
I was thoroughly disappointed when I bought a new car in 2019 and found most car manufacturers had removed CD players. They figure most people store music on bloody telephones & play crappy MP3’s.
I often buy blank CD’s. You need CD-R (CD Recordable) disks. I’ve never had a problem finding them. Usually from my local Staples store.
This is all I play in my car - MP3s burned onto CDs. I’m sure my radio still works - I just haven’t turned it on in years. I get about 140 songs on each CD - I have to change the CDs about once every two months. I prefer that to trying to remember to take my iPod with me out to the car and then back to the kitchen where it lives.
I do use iTunes to burn the CDs, though - I ran into the occasional song that wouldn’t burn, and it was simple to convert it to MP3 format.
Enjoy it while you can - we’re all going to be forced onto the Cloud sooner or later. 
Can’t you plug in a USB drive like @Dr.Strangelove says? I wouldn’t bother with a CD player either if it is easy to keep 1000 CDs’ worth of high-quality FLACs on your keychain.
There is a hiccup with some USB drives for cars. My girlfriend’s Volt does this, and my 2019 Prius also does this. For whatever reason, the car 1) ignores the folder/directory structure on the USB drive, and 2) then orders all the playable (.mp3, .wma) files alphabetically.
The program I use to convert to .mp3 files uses generic names: “track 01”,“track02” etc… So if you have, say 5 different CDs, in different folders on the USB drive, what you end up with is a play sequence like this:
track01
track01
track01
track01
track01
track02
track02
track02
track02
track02
It does an “ordered shuffle” depending on how many folders you have. Very annoying when you want to listen to one CD “through” before moving on to the next.
I have played around with the controls, and for some reason the car won’t recognize and manage the different folders.
My 2017 Toyota Corolla reads a USB just fine, and respects the folder structure.
But it must read (and cache) the entire folder structure when it loads up. This (for a 32Gb USB) takes some time.
When I start the car, it picks up playing the song it was playing when i turned the car off. But if that song ends before it has indexed and cached the next song in the album to play, it jumps back to song number one (bloody Adele, again). It’s really frustrating.
My car’s sound system no workee. I just chuck my bluetooth speaker on the front seat and play off the phone should the need arise.
Yes I can use a USB however that means transferring from CD to USB. A hassle. I do have 2 or 3 USB’s with music loaded but I generally listen to satellite radio. Haven’t heard commercial radio in at least 10 years. Don’t even own a radio in the house. Was at the dentist yesterday. It reaffirmed my decision that I not own a radio.
It might be easier to just purchase and install this radio in your car.
My local Walmart seems to be fresh out of that particular model.