Yes and no! You can add an aftermarket remote starter on manual transmission, gas or diesel. But definitely you will have a separate start fob. I always had/have remote starters on my cars with MT. There is a "setup" procedure you have to follow before you leave the car, otherwise it won't start. Depending on your model, you'll have to follow similar steps:I wonder if remote start could be added to the diesel manual and be programmed on a factory remote start fob?
1. Put the car in neutral and engage the parking brake, car must idling
2. Release the normal brake pedal and don't keep your leg on clutch either
3. Push the button on the start fob and wait for its confirmation (blinking LED, etc)
4. Take out the key from contact if the car doesn't have a Start button
5. Leave the car, close the door and lock the doors using the start fob. That will lock all doors and shout down the engine too.
In this way the car is ready to start using the remote starter. It looks complicated but you will do this in ~10 seconds. This procedure is to make sure that the car is in neutral, parking brake engaged, nobody inside, etc. Opening the door without starting the car will reset the starter so if you forget something into the car and want to start it in the morning, you need to repeat the procedure.
Professional installation is $400. Some safety features can be bypassed but I don't recommend it.