The Veloci and SLF450x vehicles have a boost option. Once you go over 60 mph, hold R to get a speed boost. Note: Handling will get difficult when this is done; using it on a straightaway may work best.

When riding the Cohete (motorcycle) and accelerating, briefly hold L to pop a wheelie. This will give you more acceleration/speed.

With any car, after you start to accelerate hold R and it will speed up your car.

After using a slipstream, press Nitrous quickly to go at least 180 mph.