Spotty and Mat have the good advice.
Launching and retrieving in the boat hole is pretty straight forward and bogging is not usually an issue and is best done in the higher half of the tide so you can get out to the main channel without running aground. Retrieve in the main channel on low tide is possible and common but care must be taken to do it clean and quick or disaster can quickly follow, especially on the lower tides. (see Spottys photo

) Some of the locals use ramps for the trailer wheels to stop them sinking in the sand or a long cable to pull the trailer out on a jockey wheel without getting the car in the water (pull at an angle to pop each trailer wheel out separately). The Abalone boats use long extended trailer bars, drive the boats on quick and get out in one smooth operation using the boat motor pushing to help start moving the trailer.
At the first sign of a problem with wheels sinking, STOP! Unhook/unload. Move the car out and start again and do it quicker this time. Do NOT spin the wheels (you instantly dig a death hole).
One good hint is to actually reverse the car and trailer back a foot when loaded just before pulling out. Easier to get the wheels moving this way and avoid bogging.
The entrance bar is best tackled at higher tides when there is often a clear channel with no breaking waves (unless the swell is pretty large).
Danger: Avoid running the bar on the outgoing tide as this makes the waves stand up steep and suddenly, especially on the lower half of the tide. Crossing can usually be done on a lower tide
as long as the tide is is running IN and the swell is not too large (maybe under 1.5m?).
Take lots of care. Sit a while on the inside and watch the rhythm of the sets and where the channel is. If in doubt, forget it. Plenty of fish inside the inlet.