Can't be lazy and search within threads so:
US version, second gen PS3 if that helps. The 15th Anniversary HVC-010 seems to have an error with mapping the turbo parts; it only supports mid- and high-level, but they're mapped to low- and mid- in the Car Settings and this does some wacky things like possibly requiring you to buying all three parts (which requires going to Car Settings for low- and then Tuning Parts for high-) or at least some pair (I already bought them all so I'm not sure which). Not sure if the regular HVC does this, I don't have one yet.
Really wish there was an easy way to send stuff like this to PDI, or at least Sony.
Were you doing one of the endurance races? 5/10/15 minute ones count for this question. I know that's not what they're supposed to do, but I'm always afraid something like this is going to happen in one of those.