Glynor, can you offer some links on that?
No. I've definitely read more than one peer-reviewed article about the subject, and they largely agreed with the consensus over at hydrogen audio. I made a half-hearted attempt to look some stuff up again tonight, but it has been a year or two since I've last looked at it. And most scientific articles are behind paywalls anyway.
If memory serves (which doesn't really help with your question) almost all samples are transparent at around -v4 with modern versions of LAME (or those that were modern a year or two ago). Certain types of music (generally electronica and some kinds of classical and jazz) tend to be more difficult to compress, and they don't generally become transparent to a trained ear until -v3 or -v2. There certainly are some well known "killer samples" that aren't transparent even at -v0 or 320kbps (and where most people can be trained to successfully ABX them with greater than random chances of success). But these are specific samples, and are exceedingly rare. People hunt them. Last I looked, there were lists, and you could count them on your hands and toes.
Does this eliminate the possiblity that there are "Olympic caliber" ears out there? Certainly not. But statistically you're much more likely to be bitten by a New Yorker who is riding on a shark while being struck by lightning than to be one of those people. Of course, I don't play the lottery either.
For the record, I generally agree. If ripping my own content, I rip to FLAC if it is anything I care about at all, and if not, then to -v1. Mostly because "why not" and because there could be some killer new format in the coming years and you can't undo loss. But when I buy stuff online and I get Amazon's nice quality -v2 MP3s, it doesn't hurt my feelings.
As I said above, though... Even if you do have an Olympic quality ear, and even if you do have a very good car stereo (both of these are very dubious), then the chances you could detect the differences between a modern LAME high-quality rip (say -v2 or better) and a FLAC of the same audio, repeatably, in an ABX test, in a moving car, approaches nil. If you're actually driving (and so your mind is busy processing all sorts of inputs), then I'd call it
absolutely zero.
If you're sitting still with the car off and listening in your car, more than occasionally, and you rip your collection specifically for these instances...? I call you weird.