2005 with several issues-- help!

hi-- I live in Los Angeles, and just got a 2005 Prius, with no owner's manual, 56,000 miles, and several problems, despite the fact that I like the car otherwise and want to keep it and get everything running properly.

Most importantly, I parked two days ago, listened to the radio for several minutes, turned it off and shortly thereafter tried to drive away but the car would not "start". It continually gave me a number of error messages, including "check engine".

I thought I might have to have it towed to the dealer or elsewhere to get it fixed, but the next morning it "started" as if without any problems, and without any error codes. I drove it for more than an hour without problems other than some error codes that appeared and disappeared periodically. Is this a problem with the 12-volt battery, with the main battery, with a bad connection, or maybe something else?

Sometimes the GPS seems to work properly, but after a few minutes it switches from the screen showing the route, to one showing a pattern of arrows in a circle, and I cannot switch it back to the map/ route.

The Bluetooth recognizes my phone, but I still cannot get it to work.

The rear view mirror does not seem to work if I understand how it is supposed to operate-- when I click the button on the bottom of the mirror, a small pilot light glows, but the mirror does not dim regardless of day, night, or whether there is anyone behind me with lights on.

Many companies have a site from which to download info, such as an owner's manual, but I have been unable to find anything like that for the Prius. Is there such a site? I have other cars where the owners have a club in which the owners share the use of a diagnostic tool to sort out problems with the On Board Diagnostics-- is there such a thing for the Prius? Should I instead try to buy a manual on eBay?

I converted a BMW to full electric power-- no engine, gas tank, muffler, etc. It's fast and very powerful-- will burn rubber from 0 to about 40 mph-- but I still have more work to do, such as installing a battery-operated power brake system. (It's on You Tube under "BMW EV Conversion Burns Rubber".) I would eventually like to adapt the Prius to a plug-in hybrid, and eventually to a fully electric plug-in-- no engine or gasoline at all.

It worries me that Toyota denies that there is any need for a brake override for the accelerator-- I hope they finally retrofit ALL of their hybrids to brake override. Especially with no mechanical ignition key... nothing but a button to push... the current system does not inspire absolute confidence. With all the problems with sudden acceleration, the simplest answer would be to put all their customers at ease with brake override-- it would be very expensive no doubt, but could save lives, and could prevent lawsuits that could be even more costly.

I would very much like to meet with other Prius owners in the Los Angeles area, and to form a Prius club if there is not already one.

Thanks!

Bill