Zion overnight parking?

Say a person wants to do big walls in Zion overnight, how did they park or shuttle? We plan on being there in mid to late April.

 Can you get an overnight parking pass from the Rangers?
I appreciate your replies. Thanks.

You can get an overnight permit from the back country desk for overnighting. This will allow you to drive in before the shuttle start running for the day. Not sure on the actual details so for the best info it's worth calling the back country desk and asking about the nittty gritty. 

I got a wall permit and they gave me something for my car. The bus will make special stops to pick up or drop off climbers (just tell the driver when you get on), so we left our car in the shuttle lot. The bus driver made an annoucement for our "special stop" and we got off the bus to the applause of the tourists. Felt like celebrities for a minute

This is what I have experienced in the last few months there. It is my understanding that you can either get a yellow pass (parking pass to put in your dash) to drive in early before the shuttles. Good for fix and fire.  Or you can get an overnight bivy permit. Not both. This is all assuming shuttles are running. If it’s the “off season”, drive in and park in good pull outs and lots. Still need bivy permit for safety and records. All of this must be done in person unfortunately. Bus drivers do not stop or pick up climbers anymore. They are pretty strict and mean about this. You might get the rare driver that’s stoked (I did 1 out of like 5 times), but don’t count on it. Especially annoying right now because several shuttle stops nearby trade routes are closed for construction. Cheers.