about your money. The IRS cares only about compliance. They and their employees never receive a dime of your taxes. They are paid to tick boxes. They are just as happy ticking the box that indicates compliance as they would be about processing another payment.

Most audits are line-item specific. If they are auditing your deduction for an electric car, then they'll only ask for documentation for that particular purchase. They're not going to ask for all your medical and business receipts.

If you point out a missed $150 deduction when they are auditing an incorrect $1000 deduction then they are still going to require that you substantiate the $1000 deduction. They MIGHT drop it if you point out a missed $1000 deduction. However, that is only because they recognize that it would be pointless. You'd simply file an amended return claiming the missed deduction to offset your incorrect deduction. No one is going to lie on that amended return because they know they are already under a microscope.

The only reason I can imagine for purposefully omitting any substantial deduction would be to avoid penalties in the event that you made a mistake. That's like spending $500 extra on a phone warranty for a phone that would only cost $500 to replace.