Forza Motorsport 5

Update: The April game update makes all of the initial 200 cars that launched with Forza 5 available as rental cars so it's no longer necessary to use the "rental glitch" if you don't own the car that is required for this achievement.

This achievement is unlocked once these 3 achievements are completed:



Go to Free Play
Car: 2012 Audi #1 Audi Team Joest R18 e-tron Quattro
Track: Le Mans - Full Circuit
Rounds: 1
Drivatar difficulty easy.

The 2012 Audi #1 Audi Team Joest R18 e-tron Quattro can be rented from the car dealership.



Go to Free Play
Car: 2013 Lotus E21
Track: Yas Marina - Full Circuit
Rounds: 1
Drivatar difficulty easy.

The Lotus E21 was gifted to VIP members in November 2013.
If you don't own the car select "Rent Car" and choose any car (the Lotus isn't available there). Then select "Buy Car" and choose the Lotus E21. Before selecting a design press "B" until you're back at the main menu of Free Play. The Lotus E21 will be your car now.
Start the race and get the gold medal to unlock the achievement.



Go to Free Play
Car: #15 Rahal Letterman Lanigan Racing Dallara DW12
Track: Indianapolis Motor Speedway - The Brickyard Speedway
Rounds: 1
Drivatar difficulty easy.

The #15 Rahal Letterman Lanigan Racing Dallara DW12 can be rented from the car dealership.

Solution worked great. The one thing I'd add is that it is also possible to cut the time you need to spend to get all of these down to the very minimum by going into "Game Options" after selecting your car and track, then set the number of laps down to 1. I didn't try this until afterwards but did confirm it worked on two different races in this and the Rarified Air collection. It also starts you in the most favorable starting position when you do this so no jockeying around to pass AI players.

Edit: After 2 more races where I set the laps down to 1 (Both at Indianapolis Brickyard) I noted that neither of the latter two started me in the #1 position, however, getting to #1 in time to finish the lap was still a breeze.