Alien Ruin fix, various cherrypicked upstream fixes

Also adds new buildmode

code/modules/vehicles/cars/car.dm

@@ -1,18 +1,34 @@
 /obj/vehicle/sealed/car
 	layer = ABOVE_MOB_LAYER
 	anchored = TRUE
+	default_driver_move = FALSE
 	var/car_traits = NONE //Bitflag for special behavior such as kidnapping
 	var/engine_sound = 'sound/vehicles/carrev.ogg'
 	var/last_enginesound_time
 	var/engine_sound_length = 20 //Set this to the length of the engine sound
 	var/escape_time = 200 //Time it takes to break out of the car
 
+/obj/vehicle/sealed/car/Initialize()
+	. = ..()
+	LoadComponent(/datum/component/riding)
+
 /obj/vehicle/sealed/car/generate_actions()
 	. = ..()
 	initialize_controller_action_type(/datum/action/vehicle/sealed/remove_key, VEHICLE_CONTROL_DRIVE)
 	if(car_traits & CAN_KIDNAP)
 		initialize_controller_action_type(/datum/action/vehicle/sealed/DumpKidnappedMobs, VEHICLE_CONTROL_DRIVE)
 
+/obj/vehicle/sealed/car/driver_move(mob/user, direction)
+	if(key_type && !is_key(inserted_key))
+		to_chat(user, "<span class='warning'>[src] has no key inserted!</span>")
+		return FALSE
+	var/datum/component/riding/R = GetComponent(/datum/component/riding)
+	R.handle_ride(user, direction)
+	if(world.time < last_enginesound_time + engine_sound_length)
+		return
+	last_enginesound_time = world.time
+	playsound(src, engine_sound, 100, TRUE)
+
 /obj/vehicle/sealed/car/MouseDrop_T(atom/dropping, mob/M)
 	if(!M.canmove || M.stat || M.restrained())
 		return FALSE
@@ -33,12 +49,6 @@
 	mob_exit(M, silent)
 	return TRUE
 
-/obj/vehicle/sealed/car/after_move(direction)
-	if(world.time < last_enginesound_time + engine_sound_length)
-		return
-	last_enginesound_time = world.time
-	playsound(src, engine_sound, 100, TRUE)
-
 /obj/vehicle/sealed/car/attacked_by(obj/item/I, mob/living/user)
 	if(!I.force)
 		return
@@ -52,7 +62,7 @@
 	if(!(car_traits & CAN_KIDNAP))
 		return
 	if(occupants[user])
-		return	
+		return
 	to_chat(user, "<span class='notice'>You start opening [src]'s trunk.</span>")
 	if(do_after(user, 30))
 		if(return_amount_of_controllers_with_flag(VEHICLE_CONTROL_KIDNAPPED))
@@ -75,4 +85,4 @@
 	if(!silent)
 		M.visible_message("<span class='warning'>[M] is forced into \the [src]!</span>")
 	M.forceMove(src)
-	add_occupant(M, VEHICLE_CONTROL_KIDNAPPED)
+	add_occupant(M, VEHICLE_CONTROL_KIDNAPPED)

code/modules/vehicles/cars/clowncar.dm

@@ -127,4 +127,4 @@
 	icon_state = initial(icon_state)
 
 /obj/vehicle/sealed/car/clowncar/proc/StopDroppingOil()
-	droppingoil = FALSE
+	droppingoil = FALSE