For this Trophy to unlock you have to complete a few tasks in both the Nissan 350Z and the Nissan Skyline GT-R (R34) which are part of the NFS Heroes pack.
Here are the names of the license plates and what you have to do to unlock them:
Under Pressure: win a race or team race in the Nissan 350Z without
being overtaken (doable with 1 friend in a private lobby)
Under Attack: complete a speed test in the Nissan 350Z without
getting eliminated (doable with 1 friend in a private lobby)
Under Control: do a 383 yard (350 m) drift in the spiral of the
Foley Street parking garage in the Nissan 350Z (can be done solo in a
private lobby)
Here an image with the map location:
Under The Influence: drive on rims for 1 mile (1.6 km) during
speedlists in the Nissan Skyline GT-R (R34)
(doable with 1 friend in a private lobby)
Under Your Skin: get 5 consecutive Takedowns on the same player in
the Nissan Skyline GT-R (R34)
(doable with 1 friend in a private lobby)
Under My Thumb: eliminate at least 2 different players during a speed
test event in the Nissan Skyline GT-R (R34)
(for this one you need 2 other players but can be
done in a private lobby)