Wow, what a story. I would be filing a police report...either that or roughin' somebody up:)
Some pics would help in determining the severity of the damage. If it is just minor scrapes on the outside of the trunk, it will most likely grow over and be fine within a year. Ginkgos are tough trees, their outer bark is pretty tough even on small trees, and they close off wounds very well. However, if they are deep wounds into the inner wood, it might be best to start over since your tree is only been in the ground a year. As far as the broken limbs, I would cut them off right before the breakage point. Unless the form is totally destroyed, it will close off the branches you cut and sprout new ones next year probably. But it all depends on the severity whether you should replant or let it be.

Sorry to get slightly off topic, but were you able to catch or identify the @%&% person? It sounds like a horrible experience!

Thank you for your responses and No we did not catch them. I will clean up the broken branches and hope it survives. Gingko is my favorite tree and I was so happy to finally have one.

Check with your insurance company. They should pay for replacement and cleanup.

If that's not an option, remove broken branches and loose pieces of bark, and then let the tree take care of the rest. Pruning the branches just beyond the breaks (topping) is not what I would do. I would follow proper pruning techniques like branch removal just beyond the branch collar (thinning cuts), and possibly pruning cuts just beyond a bud or small branch (drop crotch cuts). Hopefully, in a few years, the evidence of this event will be gone.

If you catch the idiots that did this, maybe jm can come over and help you rough 'em up a little. LOL

Geez, and I get angry at the deer for doing what comes natural to them. I probably would be spending this weekend working on a fence (even if partial) or some strategically placed boulders to protect your ginkgo and your household from the vehicular vandalism. Regarding your tree, I've done a ton of reading on the matter of tree trunk injuries--due to deer (not juvenile delinquents). To summarize, trees will most often recuperate from bark damage that covers less than 50% of the circumference of the tree. Though growth on the damaged side may be delayed or permanently stunted to some extent. Most of the experts say you should clean the wound and gently even out the scrapes (without removing any healthy bark). Then just leave it alone. Sealants of any kind do NOT seem to be recommended at all today as they are said to seal in fungi and potentially damaging microorganism. UV light and fresh air are actually very good disinfectants. That's the good news. The bad news is that your tree was hit by a car and it's difficult to say how much damage was done to the root system (animal damage is usually restricted to removal of vertical strips of dark). Though I would guess that if your tree still looks good in the next few weeks, the roots are okay and it's just a question of the tree (eventually) forming callus tissue over its wounds. Good luck! PS. I've always planted a ginkgo wherever I've lived.

I've got to disagree with the post regarding wrapping the trunk in black plastic. That would be one of the worst things you could do. The sun and air circulation helps promote new growth to cover the damaged areas. Also, you do not want to retain moisture in a damaged area of the trunk, this will only promote rot, fungus, and disease. In addition, black material would absorb heat from the sun during the winter, which in turn would heat the bark and stimulate the tissue when the bark should be dormant during the winter. This will very quickly cause more damage, as the bark heats during the day, then rapidly cools at night when the sun goes down. This is basically called sunscald, which will show up as more damgage in the spring. In conclusion....don't cover it with anything, let it do it's thing.

You need to deter repeat performances;
add some big landscape boulders to the perimeter of your property, ring the area with fencing, etc.

I wish you & your gingko (also one of my favorite trees) the best.

I also love ginkgos, and my experience is that the bark will likely heal (leave it alone!), but side branches, and any damage to the leader will create an "imperfect" specimen.
My suggestion is to dig it up this fall and place it elsewhere, if you have the space. Nothing wrong with 2 ginkgos!
Then seal off the location from further violations, and put in another.

Yes, if not a fence, then boulders, spaced so that cars can 'try' but won't actually fit. Lesson learned!

I had a customer with a corner lot that was subject to kids diving across her lawn, using it has a fun shortcut. She asked me to make a barrier to stop them. I put in some flowerbeds with some artfully placed boulders. It worked for about a year and then I got a call from her. Sure enough, some kid drove into one of the flowerbeds and got hung up on one of the boulders, putting a hole in the oil pan and leaking oil all over the place. She wanted me to fix it and the kids dad would pay for the fix. You might think the kid was in real trouble, but he wasn't. He was taking his driving test and failed the parallel parking part of it. He and the examiner had to walk back. lol

Did your Gingko survive?

I have a much smaller plant with a small area of debarking, likely gnawed by rabbit or squirrel. One week later, the plant looks ok, but I am worried about the long term health of the plant.

Stop worrying, your Gingko will be FINE! I had deer rut damage on mine several years ago.

The wound has completely closed itself off and the tree is very robust. Very interesting the different approaches to recovery from damage, ANIMALS HEAL, PLANTS NEVER HEAL, plants seal off the damaged tissue and eventually grow new, healthy living tissue around the dead tissue. NEVER apply any black tars or sealants around your tree, this only delays the recovery or worse. The tree will eventually seal off the damage and get on with its life.