hysics.add.existing(ramp, { collisionFlags: 1, mass: 0 })

          const gltf = await this.load.gltf('/assets/glb/car.glb')
          const scene = gltf.scenes[0]

          let chassis
          let tire

          scene.traverse(child => {
            if (child.isMesh) {
              if (/window/gi.test(child.name)) {
                child.material.transparent = true
                child.material.opacity = 0.5
              } else if (child.name === 'Chassis') {
                chassis = child
       