From Bali to Java by car?

Ok, so guys. I need to get to Malang. Originally I booked a ticket to Surabaya, planned to rent a car as I usually do, but none available whatsoever or horrendous prices, its Lebaran coming up. That being said, I am considering driving myself. I know the journey is 400km. I have driven such long trips before, however never across islands with my own car. My car is registered on Bali. Does this cause any trouble when crossing over to Java? I am used to driving here, I have driven rental cars on Java, so I am ok with the traffic and "rules" (I had to laugh myself). I havent driven the route from ferry port to Malang yet. How well are the roads on this route? I know the route from Surabaya to Malang, its fairly smooth, especially the tollway. Is there anything else to consider? And yes it is feasible: Petrol, plus ferry is far less than a 5 day car rental would be at the moment.