I guess the main issue about tune your own car is that most people doesn´t have any clue about the diferences about a standard setting (that one witch comes with your car), racing settings, drifting settings (for drift mode) and drifting settings (for online drifting). Also, its all dependant of your favorite set of tires, same as your driving settings and periferal device.
Even myself who tried more than 100 cars, all maxed, all tunned to it best... still learning new things every day. About LSD, optimal power band (gearbox settings, turbo level, HP range), about camber optimal angle range (benefits and counterparts), weight balance / distribuition: ballast x rear spring adjustment, brake balances, the mandatory mods for MR or RR... Its all very complex and sometimes subjective.
One exemple:
When i drifted only using the hood camera, my damper numbers was very lower than now. Because the chase view (witch im training monstly since 1 month or so) is necessary to have a less sensible car, since your control and physics sensation is much affected.
Stills, i respect who is able to find a decent setup for his needs, but this is not the majority. My suggestion is, when you´re slamming your head on the wall to make a car works, and you see someone in the same lobbie with exactly the same car working for drift, you have 2 options:
1 - Respectfully ask if he can tell you (typing or via the mic) all valors of his settings. If you both are smart, it wont take more than 5 minutes.
2 - Add him in your friend list, ask he to share his car in his " online shared cars garage", grab that car, test for yourself (offline), copy all the specs in a paper, and try the same thing into your car. At least you will have a starting pattern to work with.