+1 for EAC
You will not be able to hear the difference in the car for sure.
Also: if you use the FLAC format, your files will be huge and take up 10x more space, leaving you with less room for music on the drive. Not a big deal if they still fit, but depending on how much you want to put on there, it may be an issue.
I can hear the difference in my stereos, for absolute sure. BIG difference. Even if you have a factory stereo now, if you want to upgrade in the future, why limit yourself with an ancient Windows 3.1 era format MP3? If you're going to do it, do it right, especially starting fresh.
And as far as the storage question, a Sandisk 1TB thumb drive is under $85. A 512gb thumb drive is under $40. As cheap as storage is today, nobody cares about how much space files take up anymore. I have over 900 complete albums on a 512, all in FLAC, and there's still a bit of room left for some more.
This is the deal with MP3. It was made back in the Windows 3.1 days. Yup, even before Windows 95. "Fast" download speeds were via a 14.4kbps modem. Hard drives were $400 for a 540 meg drive. Not gig, and certainly not terabyte, but megabyte. Your average phone had probably 500x that amount of storage today! Heck, most computers back then had 386 processors and if you had 4 megs of ram, that was HUGE. 486's were around, but very expensive. And a Pentium processor in your home PC? That was almost unheard of, as they were *just* hitting the market.
Because of the limitations of the technology of the day, MP3 was doomed from the start. It should have never persisted after hard drives started being measured in scores of gigs, and internet speeds climbed over megabyte speeds. But somehow it did. Heck, even the original MS Word format, .doc, is dead and gone.
Here in 2025, especially if starting a new music collection from scratch, there is absolutely zero legitimate reason to keep using an ancient and just downright poorly implemented from the start lossy music format.