Something

  if(GetPlayerMenu(playerid) == MainMod) {
    switch(row) {
    case 0: {
    //Show nitro
    HideMenuForPlayer(Menu:MainMod, playerid);
    ShowMenuForPlayer(Nitro, playerid);
    }
    case 1: {
    //Show Hydr
    HideMenuForPlayer(Menu:MainMod, playerid);
    ShowMenuForPlayer(Hydralics, playerid);
    }
    case 2: {
    //Show Bass
    HideMenuForPlayer(Menu:MainMod, playerid);
    ShowMenuForPlayer(Bass, playerid);
    }
    case 3: {
    //Show Rims
    HideMenuForPlayer(Menu:MainMod, playerid);
    ShowMenuForPlayer(Rims, playerid);
    }
    case 4: {
    //Show Bumper
    HideMenuForPlayer(Menu:MainMod, playerid);
    ShowMenuForPlayer(Bumper, playerid);
    }
    case 5: {
    //Show Side
    HideMenuForPlayer(Menu:MainMod, playerid);
    ShowMenuForPlayer(Side, playerid);
    }
    case 6: {
    //Show Roof
    HideMenuForPlayer(Menu:MainMod, playerid);
    ShowMenuForPlayer(Nitro, playerid);
    }
    case 7: {
    //Show Exhaust
    HideMenuForPlayer(Menu:MainMod, playerid);
    ShowMenuForPlayer(Exhaust, playerid);
    }
    case 8: {
    //Show Misc
    if(GetVehicleModel(GetPlayerVehicleID(playerid)) == 534) {
    HideMenuForPlayer(Menu:MainMod, playerid);
    ShowMenuForPlayer(Misc, playerid);
    } else {
    HideMenuForPlayer(Menu:MainMod, playerid);
    ShowMenuForPlayer(MainMod, playerid);
    }
    }
    case 9: {
    //Show Exit
    HideMenuForPlayer(Menu:MainMod, playerid);
    TogglePlayerControllable(playerid, 1);
    }
	}
    }