No disrespect to the other solution, but I found one that worked instantly for me. I tried getting it in traffic for a while, but the traffic kept messing me up. Here's what worked instantly. From the Duty Roster, choose the "Single Race" option, with the following:
Vehicle Damage Off
Track Type Circuits
Number of Laps 1
Number of Opponents 1
Opponents' Vehicles Same
Opponent's Strength Easy
Choose the "Endless Autobahn" track in the Autobahn.
I used the Tribun. Just floored it out of the gate with Nitro to get up to speed and ahead of the one opponent and got it within the first 20 seconds of the race. Since there isn't any traffic, you can focus on corners and you have plenty of room.