my car does not start 80% of the time.

Your starter is the issue or a loose connection. If that's not it it's the alternator which often fails in conjunction with the battery going bad. I'm not a mechanic but I've been ripped off by them all. Cheers!

The starter contacts and plunger in the starter fail (they are replaceable)but sound like a typical failure of that OE equipment Nippon Denso starter. Charge and test the battery first to confirm it is OK and holds a charge.