Trailer-Hou

"(Shift Car)-Hou!"

- Shift Car insertion announcement

"Hissatsu! Full Throttle: Full Formula Dai-Hou!"

- Finisher announcement

The Trailer-Hou (トレーラー砲) is Kamen Rider Drive's shotgun weapon utilized when he assumes Type Formula. It first appears in episode 22. Like the Handle-Ken and Door-Ju, Shinnosuke names this weapon for what it resembles: a semi truck, with the trailer section consisting a lot of the weapon's bulk. Similar to the Shift Cars and Signal Bikes, this weapon is also sentient where it is powered by a specialized Core Driviar called the Core Driviar-TH (コア・ドライビア-TH).

Usage
The Trailer-Hou can interchange between its Trailer Mode (トレーラーモード) and Cannon Mode (大砲モード) simply by pulling down the Flame Rear Grip (フレームリアグリップ).

In Trailer Mode, the Trailer-Hou houses Shift Formula inside of its Shift Container Barrel (シフトコンテナバレル). It also utilizes a small visor called the Trailer Searcher (トレーラーサーチャー) for various purposes: searching for either Drive or Roidmudes, generating tracks in midair (being so huge, the Trailer-Hou has to generate three lanes worth of Shift Car tracks), and firing bullets from its front sides. While moving, its Generator Chassis (ジェネレーターシャーシ) tires can provide protection from Super Heavy Accelerations and its Wall Metal Body (ウォールメタルボディ) hard body can resist multiple impacts and damages.

In Cannon Mode, the Trailer-Hou can fire high output energy blasts. If Drive loads any Shift Cars into the Shift Landing Slot (シフトランディングスロット) on top of the Trailer-Hou's barrel, it announces the loaded Shift Car's name (either the form name of a Type Change Shift Car or the last name of a Tire Exchange Shift Car) followed by "Hou" (砲) and allows him to fire projectiles based on said Shift Car.

Finishing attack
The Trailer-Hou's Full Throttle finisher Trailer Impact (トレーラーインパクト) is activated when two Shift Cars are loaded into the Shutter Gate Panel (シャッターゲートパネル) slot within the Shift Container Barrel, causing the Side Gauge Window (サイドゲージウィンドウ) to display the word "FULL" before Drive pulls the Full Throttle Trigger (フルスロットルトリガー) to fire a blue laser blast that can outmatch even Mashin Chaser Triple Tune's finisher.