Need for Speed Heat

This achievement requires you to win a race with parts equipped in both auxiliary part slots.

There are two types of auxiliary parts: active and passive. Active ones are ones you can activate while driving while pressing the button, and passive ones are always active while driving that vehicle.

You will definitely unlock this throughout your completion as having both slots equipped will be vital for surviving night racing, but I'll outline the earliest / easiest way to get it if you want it out of the way. The first auxiliary parts you'll unlock will be the Kill Switch Jammer active part and the Radar Disruptor passive part. If I'm not mistaken, you'll unlock these around Rep level 10, but I'll need to confirm that.

Once you've unlocked them, they can be purchased for $10,000 each. Once you have $20,000, purchase and equip both, then head out and win a race. Once you win, you'll unlock your achievement.