Need for Speed Payback

The drag version of the Volkswagen Beetle (Derelict Car) destroys every drag related quest and Mitko effortlessly. You can make tons of mistakes, hitting bad shifts and still win. The only time I didn't win with it for the first try when I didn't paid attention and smashed into something (automatically DNF).
Try to put acceleration related cards on it, 3x chidori and 3x carbon gives additional acceleration bonuses. I don't think you need it but why not make your life easier? As for visual tuning the wheelie bars actually matter (start with a super build). If you have it, you have better control, if you don't it is even faster. I had the wheelie on and Mitko didn't have a chance. The only drawback of the car is the terrible turning in normal races so you probably have to use the handbrake all the time. Don't fear even if you take a lot of time in corners you will easily overtake anyone with the crazy acceleration and speed. In the race before the boss I smashed the car to pieces at least 4 times, went down the road all the time and still won easily. Here is my setup (you can make it even better with better cards):

https://gamerdvr.com/gamer/hun-playmore/screenshot/12289740

To earn this achievement, you need to beat the head of the Diamond Block league, Mitko Vasilev.

This is a story related achievement and it takes place in the final chapter. The races you'll be racing in are drag races, which can be annoying if you're unfamiliar with them. To be successful, you need to press the button (or whatever shift up is mapped to on your controller) right when the bar at the top is in the dark green space. If you do this, you'll gain nitrous. If you are either too early in the light green or too late in the red, you will not get nitrous, lose a bit of speed, and the bar will become shorter, making it harder to get perfect shifts.

Now onto the boss himself. I played on easy and found this to be the hardest race in the game. You'll race him in a best of 5 drag race in the last mission of his questline and he will be driving a Nissan GT-R Premium spec'd to 388. I can't tell you how much time I spent going back and forth from the race and the tuning shop trying to get my car fast enough to beat him, so here's what I ended up having:

I used an Audi R8 V10 plus spec'd to 396. Any tuning cards that boost braking or airtime are useless so avoid those at all costs. Same thing with NO2 since the car is a drag car, but for reference my NO2 Power was at 3.9.

Now what you actually need to focus on is acceleration. Even parts that make a 0.03 or 0.07 change make a huge difference. For Acceleration, my 0-60 was 1.87 and my 1/4 Mile was 8.70. I feel top speed and horsepower might not matter too much but my Horsepower was at 1034 and my Top Speed was at 223.

If you're struggling to get acceleration focused parts, go to the tuning shop and see if they have any. If not, spin the wheel and make sure you lock in acceleration so you're guaranteed to get a part with an acceleration boost.

Back to the race itself. Even with this setup I was barely squeaking past him. I was setting times around 17.1-17.2 seconds. If you're slower than that you need to hit the tuning shop asap. Also with this setup I was late on the first one or two shifts, but then was perfect each time, which is essential. If you aren't perfect after your first or second shift you might as well restart. I would shift up as much as I could until the needle started going a bit slower, then use my nitrous for the rest of the race.

Hopefully this provides some aid to people struggling with this. Just keep tuning your car and you'll get it. Also this is definitely not the best possible car you can have for this I'm sure. If anything, it might be the bare minimum acceleration requirements you need to beat him. But it's better than spending a lot of money on one of the higher end cars you unlock in this chapter.