I edited the washington map so that cars from the workshop would spawn just how normal cars do by adding the ID's into the vehicle spawn table - so far so good. Now I copied all of the workshop items into my workshop folder from my server. When I start the server I get a couple of errors and none of the cars I added spawn but I can spawn them manually ("@vehicle" command). Following Errors:

NotSupportedException: ID < 200 - SDG.Unturned.VehicleAsset..ctor (SDG.Unturned.Bundle bundle, SDG.Unturned.Data data, SDG.Unturned.Local localization, UInt16 id)
System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
System.Reflection.MonoCMethod.Invoke (BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
System.Activator.CreateInstance (System.Type type, BindingFlags bindingAttr, System.Reflection.Binder binder, System.Object[] args, System.Globalization.CultureInfo culture, System.Object[] activationAttributes)
System.Activator.CreateInstance (System.Type type, System.Object[] args, System.Object[] activationAttributes)
System.Activator.CreateInstance (System.Type type, System.Object[] args)
SDG.Unturned.Assets.loadFile (ScannedFileInfo file)
UnityEngine.Debug:LogException(Exception)
SDG.Unturned.Assets:loadFile(ScannedFileInfo)
SDG.Unturned.<init>c__Iterator0:MoveNext()
UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)

NotSupportedException: ID < 200 - SDG.Unturned.VehicleAsset..ctor (SDG.Unturned.Bundle bundle, SDG.Unturned.Data data, SDG.Unturned.Local localization, UInt16 id)
System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
System.Reflection.MonoCMethod.Invoke (BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
System.Activator.CreateInstance (System.Type type, BindingFlags bindingAttr, System.Reflection.Binder binder, System.Object[] args, System.Globalization.CultureInfo culture, System.Object[] activationAttributes)
System.Activator.CreateInstance (System.Type type, System.Object[] args, System.Object[] activationAttributes)
System.Activator.CreateInstance (System.Type type, System.Object[] args)
SDG.Unturned.Assets.loadFile (ScannedFileInfo file)
UnityEngine.Debug:LogException(Exception)
SDG.Unturned.Assets:loadFile(ScannedFileInfo)
SDG.Unturned.<init>c__Iterator0:MoveNext()
UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)

Loading server workshop assets: 32/232
NotSupportedException: ID < 200 - SDG.Unturned.VehicleAsset..ctor (SDG.Unturned.Bundle bundle, SDG.Unturned.Data data, SDG.Unturned.Local localization, UInt16 id)
System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
System.Reflection.MonoCMethod.Invoke (BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
System.Activator.CreateInstance (System.Type type, BindingFlags bindingAttr, System.Reflection.Binder binder, System.Object[] args, System.Globalization.CultureInfo culture, System.Object[] activationAttributes)
System.Activator.CreateInstance (System.Type type, System.Object[] args, System.Object[] activationAttributes)
System.Activator.CreateInstance (System.Type type, System.Object[] args)
SDG.Unturned.Assets.loadFile (ScannedFileInfo file)
UnityEngine.Debug:LogException(Exception)
SDG.Unturned.Assets:loadFile(ScannedFileInfo)
SDG.Unturned.<init>c__Iterator0:MoveNext()
UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)

NotSupportedException: ID < 200 - SDG.Unturned.VehicleAsset..ctor (SDG.Unturned.Bundle bundle, SDG.Unturned.Data data, SDG.Unturned.Local localization, UInt16 id)
System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
System.Reflection.MonoCMethod.Invoke (BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
System.Activator.CreateInstance (System.Type type, BindingFlags bindingAttr, System.Reflection.Binder binder, System.Object[] args, System.Globalization.CultureInfo culture, System.Object[] activationAttributes)
System.Activator.CreateInstance (System.Type type, System.Object[] args, System.Object[] activationAttributes)
System.Activator.CreateInstance (System.Type type, System.Object[] args)
SDG.Unturned.Assets.loadFile (ScannedFileInfo file)
UnityEngine.Debug:LogException(Exception)
SDG.Unturned.Assets:loadFile(ScannedFileInfo)
SDG.Unturned.<init>c__Iterator0:MoveNext()
UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)

NotSupportedException: ID < 200 - SDG.Unturned.VehicleAsset..ctor (SDG.Unturned.Bundle bundle, SDG.Unturned.Data data, SDG.Unturned.Local localization, UInt16 id)
System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoCMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
System.Reflection.MonoCMethod.Invoke (BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)
System.Activator.CreateInstance (System.Type type, BindingFlags bindingAttr, System.Reflection.Binder binder, System.Object[] args, System.Globalization.CultureInfo culture, System.Object[] activationAttributes)
System.Activator.CreateInstance (System.Type type, System.Object[] args, System.Object[] activationAttributes)
System.Activator.CreateInstance (System.Type type, System.Object[] args)
SDG.Unturned.Assets.loadFile (ScannedFileInfo file)
UnityEngine.Debug:LogException(Exception)
SDG.Unturned.Assets:loadFile(ScannedFileInfo)
SDG.Unturned.<init>c__Iterator0:MoveNext()
UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)

Sry for the long post, thank you very much!