diff --git a/src/Client.cpp b/src/Client.cpp
index ae0f325..d6da252 100644
--- a/src/Client.cpp
+++ b/src/Client.cpp
@@ -6,6 +6,7 @@
 // FIXME: add debug prints
 
 void TClient::DeleteCar(int Ident) {
+    std::unique_lock lock(mVehicleDataMutex);
     for (auto& v : mVehicleData) {
         if (v.ID() == Ident) {
             mVehicleData.erase(v);
@@ -15,6 +16,7 @@ void TClient::DeleteCar(int Ident) {
 }
 
 void TClient::ClearCars() {
+    std::unique_lock lock(mVehicleDataMutex);
     mVehicleData.clear();
 }
 
@@ -34,6 +36,7 @@ int TClient::GetOpenCarID() const {
 }
 
 void TClient::AddNewCar(int Ident, const std::string& Data) {
+    std::unique_lock lock(mVehicleDataMutex);
     mVehicleData.emplace(Ident, Data);
 }
 
@@ -42,6 +45,7 @@ TClient::TVehicleDataLockPair TClient::GetAllCars() {
 }
 
 std::string TClient::GetCarData(int Ident) {
+    std::unique_lock lock(mVehicleDataMutex);
     for (auto& v : mVehicleData) {
         if (v.ID() == Ident) {
             return v.Data();
@@ -52,6 +56,7 @@ std::string TClient::GetCarData(int Ident) {
 }
 
 void TClient::SetCarData(int Ident, const std::string& Data) {
+    std::unique_lock lock(mVehicleDataMutex);
     for (auto& v : mVehicleData) {
         if (v.ID() == Ident) {
             v.SetData(Data);
diff --git a/src/TServer.cpp b/src/TServer.cpp
index b03e266..a25ccf5 100644
--- a/src/TServer.cpp
+++ b/src/TServer.cpp
@@ -280,7 +280,11 @@ void TServer::ParseVehicle(TClient& c, const std::string& Pckt, TNetwork& Networ
 void TServer::Apply(TClient& c, int VID, const std::string& pckt) {
     std::string Packet = pckt.substr(pckt.find('{')), VD = c.GetCarData(VID);
     std::string Header = VD.substr(0, VD.find('{'));
-    VD = VD.substr(VD.find('{'));
+    if(VD.empty()){
+        error("Applying config for a non existing car?");
+        abort();
+    }
+    VD = VD.substr(VD.find('{')); //TODO somehow this got hit while VD is empty
     rapidjson::Document Veh, Pack;
     Veh.Parse(VD.c_str());
     if (Veh.HasParseError()) {