You can use the Duplicates by VIN History option to define a period within which invoices with the same VIN are reported.
To specify the Duplicates by VIN History period
On the Company tab, click Company Info; on the Company Settings tab, click the Duplicates by VIN History box, and then click the appropriate period from one month to one year.
To see the invoices with the same VIN
On the Operations tab, click Invoices; on the Invoices page, click the by VIN link in the Duplicates column.
On the Reports tab, click Duplicates by VIN
On the Duplicates by VIN page, in the Search pane, enter the appropriate settings, and then click Find.