Grumobile

The Grumobile is a large, rocket-powered vehicle that is used as the primary means of transport for Felonius Gru.

Appearance
The vehicle is extremely high, being as tall as a story of a building, and the cockpit is on the top of the car. Under the cockpit, it seems to be spacious (Not directly shown but implied when Gru can keep Agnes, Edith, and Margo all inside) and entrance is behind the vehicle. It can speed up instantly thanks to it's massive rocket that provides significant boost in a matter of seconds. The sound of the honk is slightly lower in amplitude compared to typical cars, more like a truck's horn.

Despicable Me
After getting a cup of coffee, Gru drives home in his Grumobile; in his way, he overtakes a man who just overtook the slow car that Gertrude drives. Then, when he heads to the Bank of Evil, he pushes cars out of their parking spaces before parking. Gru later drives the Grumobile away from Miss Hattie's Home for Girls after adopting the girls, and the flame burns a child's balloon in the process.

Some days afterwards, Gru parks near Vector's Fortress before breaking into to the young supervillain's home to retake the Shrink Ray. After the heist, Gru drives the Grumobile to Super Silly Fun Land.

Despicable Me 2
Gru heads to Eduardo Perez's Cinco de Mayo party with the Grumobile, smashing all cars parked outside the mansion. He later drives back home quickly after giving excuses to Eduardo when he gave him a chance to conquer the world with him, and the fence between his and Fred McDade's house is smashed before the vehicle parks into the yard.

Edith is seen riding around on a miniature riding toy version of the Grumobile in the girls' bedroom.

Despicable Me 3
In the first trailer, the Grumobile is seen to be able to boost the height of the whole vehicle by stretching braces attached to the wheel. It can be changed very swiftly, and it's even able to smash the nearby car away without moving the wheel.

Trivia

 * It looks very similar to Gru's Airship too, particularly in general design. However, it doesn't appear to be weaponized.