diff --git a/src/DETHRACE/common/cutscene.c b/src/DETHRACE/common/cutscene.c
index 1e3644ce..cc7b24f8 100644
--- a/src/DETHRACE/common/cutscene.c
+++ b/src/DETHRACE/common/cutscene.c
@@ -129,7 +129,7 @@ void PlaySmackerFile(char* pSmack_name) {
 void DoOpeningAnimation() {
     LOG_TRACE("()");
     PlaySmackerFile("LOGO.SMK");
-    PlaySmackerFile("MIX_INTR.SMK");
+    PlaySmackerFile(harness_game_mode.intro_smk_file);
     return WaitForNoKeys();
 }
 
diff --git a/src/DETHRACE/common/graphics.c b/src/DETHRACE/common/graphics.c
index 181d0922..9d3066bd 100644
--- a/src/DETHRACE/common/graphics.c
+++ b/src/DETHRACE/common/graphics.c
@@ -1410,7 +1410,14 @@ void ShadowMode() {
 // IDA: int __cdecl SwitchToRealResolution()
 int SwitchToRealResolution() {
     LOG_TRACE("()");
-    NOT_IMPLEMENTED();
+
+    if (gGraf_data_index == gReal_graf_data_index) {
+        return 0;
+    }
+    gGraf_data_index = gReal_graf_data_index;
+    gGraf_spec_index = gReal_graf_data_index;
+    gCurrent_graf_data = &gGraf_data[gReal_graf_data_index];
+    return 1;
 }
 
 // IDA: int __cdecl SwitchToLoresMode()
diff --git a/src/DETHRACE/common/loading.c b/src/DETHRACE/common/loading.c
index b40b4a0b..2b69965f 100644
--- a/src/DETHRACE/common/loading.c
+++ b/src/DETHRACE/common/loading.c
@@ -1445,7 +1445,7 @@ void GetAString(FILE* pF, char* pString) {
 // IDA: void __cdecl AboutToLoadFirstCar()
 void AboutToLoadFirstCar() {
     LOG_TRACE("()");
-    NOT_IMPLEMENTED();
+    memset(gFunk_groove_flags, 0, sizeof(gFunk_groove_flags));
 }
 
 // IDA: void __usercall LoadOpponentsCars(tRace_info *pRace_info@<EAX>)
@@ -1663,6 +1663,11 @@ int TestForOriginalCarmaCDinDrive() {
     tPath_name paths_txt;
     int paths_txt_first_char;
 
+    // JeffH: Added to optionally bypass this check
+    if (!harness_enable_cd_check) {
+        return 1;
+    }
+
     paths_txt[0] = 0;
     strcat(paths_txt, gApplication_path);
     strcat(paths_txt, gDir_separator);
@@ -1703,14 +1708,8 @@ int TestForOriginalCarmaCDinDrive() {
         return 0;
     }
 
-    if (Harness_GameMode() == eGame_mode_SplatPack) {
-        if (!PDCheckDriveExists2(cutscene_pathname, "SPLINTRO.SMK", 2000000)) {
-            return 0;
-        }
-    } else {
-        if (!PDCheckDriveExists2(cutscene_pathname, "MIX_INTR.SMK", 2000000)) {
-            return 0;
-        }
+    if (!PDCheckDriveExists2(cutscene_pathname, harness_game_mode.intro_smk_file, 2000000)) {
+        return 0;
     }
 
     if (paths_txt_first_char != '@') {
diff --git a/src/DETHRACE/common/main.c b/src/DETHRACE/common/main.c
index 231c3b1f..33c7b290 100644
--- a/src/DETHRACE/common/main.c
+++ b/src/DETHRACE/common/main.c
@@ -76,7 +76,6 @@ void GameMain(int pArgc, char** pArgv) {
     strcat(gApplication_path, "DATA");
 
     UsePathFileToDetermineIfFullInstallation();
-
     if (!gCD_fully_installed && GetCDPathFromPathsTxtFile(CD_dir) && !PDCheckDriveExists(CD_dir)) {
         PDInitialiseSystem();
         fprintf(stderr, "Can't find the Carmageddon CD\n");
diff --git a/src/DETHRACE/common/sound.c b/src/DETHRACE/common/sound.c
index 8a801b1f..c2007e85 100644
--- a/src/DETHRACE/common/sound.c
+++ b/src/DETHRACE/common/sound.c
@@ -46,11 +46,10 @@ void UsePathFileToDetermineIfFullInstallation() {
     strcat(path_file, gDir_separator);
     strcat(path_file, "PATHS.TXT");
 
-    if (PDCheckDriveExists(path_file) == 0) {
+    if (PDCheckDriveExists(path_file)) {
         fp = fopen(path_file, "rt");
         if (fp != NULL) {
             if (GetALineWithNoPossibleService(fp, line2) && GetALineWithNoPossibleService(fp, line2) && GetALineWithNoPossibleService(fp, line3) && strcmp(line3, "Full") == 0) {
-
                 gCD_fully_installed = 1;
             }
             fclose(fp);
diff --git a/src/DETHRACE/main.c b/src/DETHRACE/main.c
index 177cc692..f76b139d 100644
--- a/src/DETHRACE/main.c
+++ b/src/DETHRACE/main.c
@@ -9,8 +9,6 @@ extern int original_main(int pArgc, char* pArgv[]);
 int main(int argc, char* argv[]) {
     int result;
 
-    Harness_Init(argv[0], &OpenGLRenderer);
-
     char* root_dir = getenv("DETHRACE_ROOT_DIR");
     if (!root_dir) {
         LOG_PANIC("DETHRACE_ROOT_DIR is not set");
@@ -21,5 +19,7 @@ int main(int argc, char* argv[]) {
         LOG_PANIC("Failed to chdir. Returned %d", result);
     }
 
+    Harness_Init(argv[0], &OpenGLRenderer);
+
     return original_main(argc, argv);
 }
diff --git a/src/DETHRACE/pc-dos/dossys.c b/src/DETHRACE/pc-dos/dossys.c
index 42cf95ac..730a5bc2 100644
--- a/src/DETHRACE/pc-dos/dossys.c
+++ b/src/DETHRACE/pc-dos/dossys.c
@@ -611,6 +611,11 @@ int original_main(int pArgc, char** pArgv) {
     float f;
 
     for (i = 1; i < pArgc; i++) {
+
+        if (Harness_Hook_HandleCommandLineArg(pArgv[i])) {
+            continue;
+        }
+
         if (strcasecmp(pArgv[i], "-hires") == 0) {
             gGraf_spec_index = 1;
         } else if (strcasecmp(pArgv[i], "-yon") == 0 && i < pArgc - 1) {
diff --git a/src/harness/harness.c b/src/harness/harness.c
index 9db19f02..7e8d4d0f 100644
--- a/src/harness/harness.c
+++ b/src/harness/harness.c
@@ -2,25 +2,44 @@
 #include "harness.h"
 #include "input/keyboard.h"
 #include "stack_trace_handler.h"
+#include "unistd.h"
+#include <sys/stat.h>
 
 SDL_Window* window;
 renderer* current_renderer;
 br_pixelmap* palette;
 uint32_t* screen_buffer;
-eGame_mode game_mode;
 
 br_pixelmap* last_dst = NULL;
 br_pixelmap* last_src = NULL;
 
+// if not 0, enable the original CD check code, otherwise just skip
+int harness_enable_cd_check;
+
+// SplatPack or Carmageddon. This is where we represent the code differences between the two. For example, the intro smack file.
+tHarness_GameMode harness_game_mode;
+
+void Harness_DetectGameMode() {
+    if (access("DATA/CUTSCENE/SPLINTRO.SMK", F_OK) != -1) {
+        harness_game_mode.name = "Splat Pack";
+        harness_game_mode.intro_smk_file = "SPLINTRO.SMK";
+    } else {
+        harness_game_mode.name = "Carmageddon";
+        harness_game_mode.intro_smk_file = "MIX_INTR.SMK";
+    }
+    LOG_INFO("\"%s\"", harness_game_mode.name);
+}
+
 void Harness_Init(char* name, renderer* renderer) {
     install_signal_handler(name);
     current_renderer = renderer;
     screen_buffer = NULL;
-    game_mode = eGame_mode_Carmageddon;
 
     if (SDL_Init(SDL_INIT_TIMER) != 0) {
         LOG_PANIC("SDL_INIT_TIMER error: %s", SDL_GetError());
     }
+
+    Harness_DetectGameMode();
 }
 
 void Harness_PumpEvents() {
@@ -41,8 +60,12 @@ void Harness_PumpEvents() {
     }
 }
 
-eGame_mode Harness_GameMode() {
-    return game_mode;
+int Harness_Hook_HandleCommandLineArg(char* arg) {
+    if (strcasecmp(arg, "-cdcheck") == 0) {
+        harness_enable_cd_check = 1;
+        return 1;
+    }
+    return 0;
 }
 
 void Harness_Hook_DOSGfxBegin() {
diff --git a/src/harness/harness.h b/src/harness/harness.h
index 94c5f760..591671ec 100644
--- a/src/harness/harness.h
+++ b/src/harness/harness.h
@@ -5,25 +5,24 @@
 #include "debug.h"
 #include <SDL2/SDL.h>
 
-typedef int harness_game_func(void*);
-
 typedef struct renderer {
     int (*get_window_flags)();
     void (*init)(SDL_Window* window);
     void (*doubleBuffer)(uint32_t* src, SDL_Window* window);
 } renderer;
 
-typedef enum eGame_mode {
-    eGame_mode_Carmageddon,
-    eGame_mode_SplatPack
-} eGame_mode;
+typedef struct tHarness_GameMode {
+    char* name;
+    char* intro_smk_file;
+} tHarness_GameMode;
+
+extern tHarness_GameMode harness_game_mode;
+extern int harness_enable_cd_check;
 
 void Harness_Init(char* name, renderer* renderer);
-void Harness_RunWindowLoop(harness_game_func* game_func, void* arg);
-
-eGame_mode Harness_GameMode();
 
 // Hooks are called from original game code.
+int Harness_Hook_HandleCommandLineArg(char* arg);
 void Harness_Hook_DOSGfxBegin();
 void Harness_Hook_BrDevPaletteSetOld(br_pixelmap* pm);
 void Harness_Hook_BrDevPaletteSetEntryOld(int i, br_colour colour);