Replace the vehicles.meta entries in update.rpf/common/data/levels/gta5 with the ones provided here:

Prison Bus entry:

    <Item>
      <modelName>pbus</modelName>
      <txdName>pbus</txdName>
      <handlingId>PBUS</handlingId>
      <gameName>PBUS</gameName>
      <vehicleMakeName />
      <expressionDictName>null</expressionDictName>
      <expressionName>null</expressionName>
      <animConvRoofDictName>null</animConvRoofDictName>
      <animConvRoofName>null</animConvRoofName>
      <animConvRoofWindowsAffected />
      <ptfxAssetName>null</ptfxAssetName>
      <audioNameHash />
      <layout>LAYOUT_PRISON_BUS</layout>
      <coverBoundOffsets>PBUS_COVER_OFFSET_INFO</coverBoundOffsets>
      <explosionInfo>EXPLOSION_INFO_TRUCK</explosionInfo>
      <scenarioLayout />
      <cameraName>DEFAULT_FOLLOW_VEHICLE_CAMERA</cameraName>
      <aimCameraName>BOX_VEHICLE_AIM_CAMERA</aimCameraName>
      <bonnetCameraName>DEFAULT_VEHICLE_BONNET_CAMERA</bonnetCameraName>
      <povCameraName>BUS_POV_CAMERA</povCameraName>
      <FirstPersonDriveByIKOffset x="0.000000" y="-0.040000" z="0.000000" />
      <FirstPersonDriveByUnarmedIKOffset x="0.000000" y="-0.100000" z="0.000000" />
	  <FirstPersonProjectileDriveByIKOffset x="0.000000" y="0.000000" z="0.000000" />
	  <FirstPersonProjectileDriveByPassengerIKOffset x="0.000000" y="0.000000" z="0.000000" />
	  <FirstPersonProjectileDriveByRearLeftIKOffset x="0.000000" y="0.000000" z="0.000000" />
	  <FirstPersonProjectileDriveByRearRightIKOffset x="0.000000" y="0.000000" z="0.000000" />
	  <FirstPersonDriveByLeftPassengerIKOffset x="0.000000" y="0.000000" z="-0.060000" />
	  <FirstPersonDriveByRightPassengerIKOffset x="0.000000" y="0.000000" z="-0.043000" />
	  <FirstPersonDriveByRightRearPassengerIKOffset x="0.000000" y="0.000000" z="-0.043000" />
	  <FirstPersonDriveByLeftPassengerUnarmedIKOffset x="0.000000" y="-0.100000" z="0.000000" />
	  <FirstPersonDriveByRightPassengerUnarmedIKOffset x="0.000000" y="-0.100000" z="0.000000" />
	  <FirstPersonMobilePhoneOffset x="0.133000" y="0.176000" z="0.508000" />
      <FirstPersonPassengerMobilePhoneOffset x="0.136000" y="0.163000" z="0.648000" />
      <PovCameraOffset x="0.000000" y="-0.165000" z="0.630000" />
      <PovCameraVerticalAdjustmentForRollCage value="0.000000" />
      <PovPassengerCameraOffset x="0.000000" y="0.100000" z="0.185000" />
      <PovRearPassengerCameraOffset x="0.000000" y="0.100000" z="0.235000" />
      <vfxInfoName>VFXVEHICLEINFO_TRUCK_GENERIC</vfxInfoName>
      <shouldUseCinematicViewMode value="true" />
      <shouldCameraTransitionOnClimbUpDown value="false" />
      <shouldCameraIgnoreExiting value="false" />
      <AllowPretendOccupants value="true" />
      <AllowJoyriding value="false" />
      <AllowSundayDriving value="false" />
      <AllowBodyColorMapping value="true" />
      <wheelScale value="0.323700" />
      <wheelScaleRear value="0.323700" />
      <dirtLevelMin value="0.300000" />
      <dirtLevelMax value="0.850000" />
      <envEffScaleMin value="0.000000" />
      <envEffScaleMax value="1.000000" />
      <envEffScaleMin2 value="0.000000" />
      <envEffScaleMax2 value="1.000000" />
      <damageMapScale value="0.600000" />
      <damageOffsetScale value="1.000000" />
      <diffuseTint value="0x00FFFFFF" />
      <steerWheelMult value="1.000000" />
      <HDTextureDist value="5.000000" />
      <lodDistances content="float_array">
        20.000000	
        35.000000	
        90.000000	
        180.000000	
        500.000000	
        500.000000
      </lodDistances>
      <minSeatHeight value="1.513" />
      <identicalModelSpawnDistance value="20" />
      <maxNumOfSameColor value="10" />
      <defaultBodyHealth value="1000.000000" />
      <pretendOccupantsScale value="1.000000" />
      <visibleSpawnDistScale value="1.000000" />
      <trackerPathWidth value="2.000000" />
      <weaponForceMult value="1.000000" />
      <frequency value="10" />
      <swankness>SWANKNESS_1</swankness>
      <maxNum value="5" />
      <flags>FLAG_BIG FLAG_AVOID_TURNS FLAG_HAS_LIVERY FLAG_PEDS_CAN_STAND_ON_TOP FLAG_DONT_SPAWN_IN_CARGEN FLAG_USE_FAT_INTERIOR_LIGHT FLAG_BLOCK_FROM_ATTRACTOR_SCENARIO FLAG_USE_FULL_ANIMS_FOR_MP_WARP_ENTRY_POINTS</flags>
      <type>VEHICLE_TYPE_CAR</type>
      <plateType>VPT_FRONT_AND_BACK_PLATES</plateType>
	  <dashboardType>VDT_TRUCK</dashboardType>
      <vehicleClass>VC_EMERGENCY</vehicleClass>
      <wheelType>VWT_SPORT</wheelType>
      <trailers />
      <additionalTrailers />
      <drivers>
        <Item>
          <driverName>S_M_M_G6PrisGrd_01</driverName>
          <npcName />
        </Item>
      </drivers>
      <extraIncludes />
      <doorsWithCollisionWhenClosed />
      <driveableDoors />
      <bumpersNeedToCollideWithMap value="false" />
      <needsRopeTexture value="false" />
      <requiredExtras />
      <rewards>
           <Item>REWARD_WEAPON_STUNGUN</Item>
           <Item>REWARD_AMMO_STUNGUN</Item>
           <Item>REWARD_STAT_WEAPON</Item>
      </rewards>
      <cinematicPartCamera>
        <Item>WHEEL_WIDE_REAR_RIGHT_CAMERA</Item>
        <Item>WHEEL_WIDE_REAR_LEFT_CAMERA</Item>
      </cinematicPartCamera>
      <NmBraceOverrideSet>Truck</NmBraceOverrideSet>
      <buoyancySphereOffset x="0.000000" y="0.000000" z="0.000000" />
      <buoyancySphereSizeScale value="1.000000" />
      <pOverrideRagdollThreshold type="NULL" />
	  <firstPersonDrivebyData>
        <Item>BUS_PRISON_DRIVER</Item>
        <Item>BUS_PRISON_PASSENGER_RIGHT_OPEN</Item>
        <Item>BUS_PRISON_PASSENGER_LEFT_OPEN</Item>
        <Item>BUS_PRISON_PASSENGER_RIGHT_OPEN</Item>
        <Item>BUS_PRISON_PASSENGER_LEFT_OPEN</Item>
        <Item>BUS_PRISON_PASSENGER_RIGHT_OPEN</Item>
        <Item>BUS_PRISON_PASSENGER_LEFT_OPEN</Item>
        <Item>BUS_PRISON_PASSENGER_RIGHT_OPEN</Item>
        <Item>BUS_PRISON_PASSENGER_LEFT_OPEN</Item>
        <Item>BUS_PRISON_PASSENGER_RIGHT_OPEN</Item>
      </firstPersonDrivebyData>
    </Item>
