Keep playing 1-3 regular missions until a challenge pops up. If its a easy medium or hard one select no, click top left corner and go to menu. Play again and new challenge will appear. Keep doing this until you have an extreme challenge. If you think youre going to fail it, you can also back out and find a new challenge.
Now keep boosting all the time (overtaking is better as you get nonstop boost but also riskier in causing yourself to get trapped). It really comes down to some luck and the right challenge. I've done 6 extreme ones. Once I got stuck, one time it wouldn't pick up one coin and 3 times I didn't have enough time. 6th time I finished with 3 minutes 25 left.
For Extreme challenges, you need to collect 4 coins and make it to the finish line. For this achievement specific, you also nee to have 30 seconds or more to spare. Therefore it is not possible to purchase extend timers as they only last 30 seconds and can be purchased once you are out of time.
Some additional tips:
-Use U-turns or boosts on other cars to get them out of the way.
- Look ahead to make decisions
- Always have your current car selected when making a turn (Left down right or up) and keep it selected until the turn is made. I've had numerous occasions where It would follow the order when I had done U-turns on other cars in between me selecting a turn and my car actually making (or in this case not making) the turn.
-As mentioned, if you don't think you will make it just click in the top left corner to back out to the menu and restart until you get an extreme challenge again.
-Be careful with overtaking. Don't wait for a traffic light while overtaking as that will most likely cause a traffic jam and can either result in time loss or failing the mission altogether. Also when overtaking a few cars after oneanother, be sure to get rid of any cars who drive towards you as when you get stopped by that car you might have to wait for all the cars you just overtook to pass you again.
- Just keep trying. You need to get a bit experienced with the game even though it seems very simply without learning curve. Besides it comes down to getting the right challenge as some medium challenges are much harder than some extreme challenges and vice versa. Just pray for a decent set up and keep trying until you get it.
- You can pause the game to look around and get an idea of what to do. (Suggested in the comments)