Seek advice from BASC And a DEFENCE BRIEF. I dare say that in the end, the owner of the vehicle wants a new window.
In English law, the owner of the vehicle committed the offence of unnecessary obstruction, and you may have part defence to "criminal damage". In the first instance, you ought to have called the law men who (in England) would have towed the vehicle away.
Getting your vehicle off the drive is more essential than getting it on, did your wife need to go somewhere in an emergency? Things like that add weight to your argument for justifying the damage.

If the person suffering the damage only wants a window, ask to speak to them first. Offer to pay for a new window (that doesn't amount to an admission) and without a complaintant for the damage, there is no offence to charge.

Discuss with a brief first.