Not safe to drive without any plate number due to COMELEC checkpoints, no plate no travel policy, and some hulidap cops along the way. You might also encounter some " Nice People Around" checkpoints especially in Quezon, Bicol, Samar, Leyte, Surigao areas, but they are motorist friendly.
We done this before,we got out dmax at isuzu pasig then travel it by land from manila to davao. With " FOR REGISTRATION only" plate. As long the papers are complete. We only had problem when we reached davao, The papers i mean travel permit that was given to us by the isuzu was not the original copy.it was a photo copy of it. We fine for about 4000pesos but it was refunded by isuzu. Anyway if its brand new, with complete travel documents and permit i didnt see any problem travelling with your car. But be carefull especially election is fast approaching. I advised you to travel after the election. Marami kasing check point na madadaanan before you reached davao.