No. Don't dispute unless you know beyond any doubt, and can prove it, that the car wasn't repo'd or CO'd. One danger in disputing is an erasure of account (can lose important history). Another is updated lates either by the OC adding more lates, or changing or updating a status which could cause a score to drop. Moreover, the account could update to where FICO is seeing it as a new account causing a large drop in score.
If the balance is $0, send Triad a GW letter. If you tried that, do it again and again and again and again until you bug them enough to cause a change.
If the balance isn't $0, offer a PFD to have it deleted.