Well, I just skimmed the thread and now I think I can give my insight. There's quite a few of the games mentioned that I actually have played and I own.
Penny Racers (PS2): In the US, this is actually called "Gadget Racers". It's actually the first in a racing game series developed by Takara called "Choro Q HG". Yeah, kinda an odd name of a series. Anyway, my earliest memory of this game was playing it at a friends house shortly after his mom bought him a new PS2 and before I got mine. We played mainly 2 player and I had fun with it to a point that I picked my own copy out at a Gamestop my dad took me when I was little. It was addicting to me, the physics were quite good for an arcade racer, the challenges and races were fun, the small cars were cute, I loved the soundtrack, and I had a lot of laughs. Really, this is a silly game; you can even drive a chicken leg in it.
Corvette Evolution GT (PS2): I got this thinking it was a sequel to the "Corvette" racing game and it wasn't. Though I did like the car selection and the gameplay style. Though I had a hard time adjusting to the physics and I recall some of the car models in this game being horrible. Really, this game had one of the worst models of a C6 Corvette I have ever seen.
R: Racing Evolution (PS2): I rented this back when I had gamefly and I recall having fun with the game, thought I didn't play it that much unfortunately. I might go look for it later on and buy it.
DT Racer: The Enzo like car on the cover drew me into getting this for my PS2 and I played it a couple of times before shelving it. Then, I eventually sold it to gamestop for a few dollars. I was a kid when I played this and I couldn't get past the physics. So, I just called it quits after trying it a couple of times.
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Now, here's a title that I'm not sure how known it is.
This was one of the most fun racing games I played as a kid. Also, it's the only Hotwheels game I ever played. Though granted, I enjoyed it more for battle mode than for the racing. I loved the multiple arenas that you could battle hw cars in along with the powerups. My friends and I had quite a few fun nights battling each other in this game. I recently bought it at a game shop and it's still quite fun, though the physics aren't the best.