If they still own it I would leave it on the schedule. Don't claim any depreciation expense.

Sometimes, easy is not so easy. 

Is the vehicle titled in the name of the business?  If so, is it still covered on company's insurance? 

If fully depreciated, (and you didn't have some of that decades old ITC where you reduced depreciable basis), dispose of it with a $.00 selling price.

I've been known to sell the asset in the prior year (after filing return), at no gain, and THEN transfer that client to current year to begin work on it.

If you use FAM, it is easy...just right click on asset and hit delete.  And make necessary general journal entries to reflect the 'abandonment'.

leave it on the assets with no depreciation. QBI deduction includes fully depreciated assets. 

@dd4vols OP said they did not dispose it.

Last time I saw such an asset "no longer used in the business" it was because the daughter took it to college with her...

"Last time I saw such an asset "no longer used in the business" it was because the daughter took it to college with her..."

Come on, don't go kidding around - that kind of stuff never happens with our sophisticated client base 😜