Most twin engine aircraft offered oil accumulators as an option for unfeathering the props after an engine shutdown. (most handy on a training AC). When I was in to VW's, a company offered them for the engine oil. When you shut the engine down it would capture "X" amount of oil in the accumulator and just prior to starting it again you would pull a knob and it would pre-oil the bearings with oil captured under pressure at shut down. Have you ever seen this used in the Toyota PU's? And, if so, where is the source for them. BTW, this would make the need for need for anti-drain valves in the oil filters a mute point IMHO.
Jarhead