diff --git a/SkinManagerMod/CommsRadioSkinSwitcher.cs b/SkinManagerMod/CommsRadioSkinSwitcher.cs
index 1b22072..a1fbed9 100644
--- a/SkinManagerMod/CommsRadioSkinSwitcher.cs
+++ b/SkinManagerMod/CommsRadioSkinSwitcher.cs
@@ -7,6 +7,7 @@
 using DV.ThingTypes;
 using DV.UserManagement;
 using HarmonyLib;
+using SMShared;
 using UnityEngine;
 using static DV.Common.GameFeatureFlags;
 
@@ -456,10 +457,9 @@ private void ApplySelectedSkin()
             SkinManager.ApplySkin(SelectedCar, SelectedSkin, AreaToPaint);
             //CurrentThemeName = SelectedSkin.name;
 
-            if (CarTypes.IsMUSteamLocomotive(SelectedCar.carType) && SelectedCar.rearCoupler.IsCoupled())
+            if (SelectedCar.rearCoupler.IsCoupled() && (SelectedCar.rearCoupler.coupledTo?.train is TrainCar attachedCar))
             {
-                TrainCar attachedCar = SelectedCar.rearCoupler.coupledTo?.train;
-                if ((attachedCar != null) && CarTypes.IsTender(attachedCar.carLivery))
+                if (CarTypes.IsMUSteamLocomotive(SelectedCar.carType) && CarTypes.IsTender(attachedCar.carLivery))
                 {
                     // car attached behind loco is tender
                     if (SelectedSkin.SupportsVehicle(attachedCar.carLivery))
@@ -468,6 +468,14 @@ private void ApplySelectedSkin()
                         SkinManager.ApplySkin(attachedCar, SelectedSkin, AreaToPaint);
                     }
                 }
+                else if ((SelectedCar.carLivery.id == Constants.DE6_LIVERY_ID) && CarTypes.IsSlug(attachedCar.carLivery))
+                {
+                    // car attached behind DE6 is slug
+                    if (SelectedSkin.SupportsVehicle(attachedCar.carLivery))
+                    {
+                        SkinManager.ApplySkin(attachedCar, SelectedSkin, AreaToPaint);
+                    }
+                }
             }
         }
 
diff --git a/SkinManagerMod/CustomPaintTheme.cs b/SkinManagerMod/CustomPaintTheme.cs
index 2f89c89..8cdeeef 100644
--- a/SkinManagerMod/CustomPaintTheme.cs
+++ b/SkinManagerMod/CustomPaintTheme.cs
@@ -1,6 +1,7 @@
 using DV;
 using DV.Customization.Paint;
 using DV.ThingTypes;
+using SMShared;
 using System.Collections.Generic;
 using System.Linq;
 using UnityEngine;
@@ -16,8 +17,12 @@ public class CustomPaintTheme : PaintTheme
         public void RemoveSkin(Skin skin) => _skins.Remove(skin.LiveryId);
         public void RemoveSkin(string liveryId) => _skins.Remove(liveryId);
 
-        public bool SupportsVehicle(string liveryId) => _skins.ContainsKey(liveryId);
-        public bool SupportsVehicle(TrainCarLivery livery) => _skins.ContainsKey(livery.id);
+        public bool SupportsVehicle(string liveryId)
+        {
+            if (_skins.ContainsKey(liveryId)) return true;
+            return Main.Settings.allowDE6SkinsForSlug && (liveryId == Constants.SLUG_LIVERY_ID) && _skins.ContainsKey(Constants.DE6_LIVERY_ID);
+        }
+        public bool SupportsVehicle(TrainCarLivery livery) => SupportsVehicle(livery.id);
 
         public IEnumerable<TrainCarLivery> SupportedCarTypes => Globals.G.Types.Liveries.Where(type => _skins.ContainsKey(type.id));
 
@@ -29,6 +34,13 @@ public void Apply(GameObject target, TrainCar train)
 
                 ApplyToTransform(target, skin, defaultSkin);
             }
+            else if ((train.carLivery.id == Constants.SLUG_LIVERY_ID) &&
+                Main.Settings.allowDE6SkinsForSlug &&
+                _skins.TryGetValue(Constants.DE6_LIVERY_ID, out skin))
+            {
+                var defaultSkin = CarMaterialData.GetDataForCar(Constants.SLUG_LIVERY_ID);
+                ApplyToTransform(target, skin, defaultSkin);
+            }
         }
 
         private static void ApplyToTransform(GameObject objectRoot, Skin skin, CarMaterialData defaults)
diff --git a/SkinManagerMod/SkinProvider.cs b/SkinManagerMod/SkinProvider.cs
index fef93e9..9d3163a 100644
--- a/SkinManagerMod/SkinProvider.cs
+++ b/SkinManagerMod/SkinProvider.cs
@@ -236,7 +236,7 @@ public static List<CustomPaintTheme> GetSkinsForType(string carId, bool includeD
 
             if (includeDefault)
             {
-                if (IsThemeable(carId))
+                if (IsThemeable(carId) || (Main.Settings.allowDE6SkinsForSlug && (carId == Constants.SLUG_LIVERY_ID)))
                 {
                     result.AddRange(BuiltInThemeNames);
                 }