I think the fun part for me will be figuring out how to do the crashing sounds in post. I haven't done much Foley work before, so it should be fun to try.

This is what I would try:
take a board and mount it to the dashboard so that it extends to the passenger seat. spread some glass shards on the board and the dashboard. Set an old cheap camcorder on the board but just set it there, unmounted, film the actor hitting something with 2 miles per hour, the camera and the glass shards will bounce around. then cut that footage into the sequence. it will most likely be very short but could give the desired effect of being inside the car.
I don't know if it works - but should be fun to try...

make a false tree (something very light) and just run against it.
then manage to do the cut with another view (bumping a concrete wall and filming from a hole inside the wall)
then manage to get the car against a real tree for the "after" shots.

Parked car + guy in a tree suit. It's all in the perspective.

No kidding! In the first place, most cities have by-laws that frown upon crashing a car purposedly into a tree (even if it's on your property); secondly the impact could damage the tree and it could fall on a neighbour's house three years later. This has so many liability and lawsuit issues my lawyer wouldn't touch it with a ten-foot pole.

J.

I'm guessing that, unless the film is called "The Guy Who Crashed His Car into A Tree", the crash is not remotely essential to the plot - and if it is, there's no real need to show it.

J.

An already-wrecked car driving into a tree?

Yep, Jacques points out one of the three problems with doing it backwards (although that's safest [other than not doing it at all or hiring a professional]) -- the car won't "uncrumple" as it backs away from the tree.

Secondly, the car will not instantly be at full speed, so when reversed, it'll look as if it hit the brakes before crashing and slows to a smooth stop. You can ramp the speed in post but it will never look like it's going from 70-0 in an instant.

Finally, if a real car hits a tree the rear end will likely rise -- sort of like a reverse wheelie. You'll not get this effect doing it backwards. Also it'll deflect and bounce a little, which also won't happen in reverse.

All in all, difficult to make look convincing.

Jacques, I like where your head is at...let's make THAT film.

Make the tree hit the car! Brilliant!

anyways, the car doesn't HAVE to crumple in that shot. if the viewer sees the car zooming right up to the tree with a quick cut to the car smashing at a different angle, no one will know the wiser. also, the act of hitting the gas in reverse will raise the backend slightly due to the really soft springs these cars utilize. and the deflection/actual hit can be a separate shot. it doesn't have to be one flawless motion. jagged and abstract, if done right, could have more of an impact. so to speak.

I like the use of glass bits and loose camcorder. what if, for the sake of the camera, it was mounted to something that let it flop around without falling and breaking? just slam on the brakes and let the glass fly around. depending on how the camera falls it could look really cool.

This is still a bad idea unless of course your film is titled, "How I killed a tractor driver with a tree and my Marquis". Yeah, I'd watch that.

How about showing the crash form the tree's perspective? Shot of the car speeding towards the tree, then zoomed-in shot of the car "speeding" (in post) towards you. The zoom (with maybe a 2x adapter) will in fact give you several meters of clearance while the car seems to be right on top of you. When the grill fills the screen (maybe keep it out of focus for effect) you do a quick fade to black as if light was blocked out by the car. Then put in crashing and smashing sounds, or maybe cut to the inside of the car as your crew lets the back drop a foot, glass and debris flying about the inside and your actor flopping in the seat. Then outside shot of the crumpled car.

No tree or actor gets hurt in the making of this film.

how am I gonna get hurt pushing it into a tree with a tractor? it's no different than digging into a big pile of rock hard dirt. It wont be fast, that's what post is for. I think this is going to turn out great.

I like the idea of the trees perspective as well. with increased zoom, don't you loose depth perception? I might experiment with shooting head on from a distance, zoomed in to frame it as if I was close, with the tree partway in the shot. the car could stop a considerable distance from the tree and it MIGHT look as if it were much closer

I can think of so many ways of doing this without a real car its not funny.

Heres One:
1. Buy a model of your car (10" or something, not hot wheels at 2")
2. Buy a Ken doll (or similar, whatever fits in the car)
3. Get a small tree branch or small tree (green peace will hate you for it, but less so than your initial full-life concept).
4. Weight the model with lead/brass weights and get a ramp.
5. Fire the car down the ramp into your "tree"
6. No Adobe After effect? Use Perspective Shooting.

You can do some close ups of driving towards the tree in real life, but don't hit a full size car with the tree, that is just about the stupidest thing you could do for ~0.6secs of effects.

Or call someone like "Myth Busters" I'm sure you could make up a silly "Myth" about a car hitting a tree and ask them to prove it out for you (you provide them the car, and on condition you get you use the footage in a non-compete manner). Who knows, maybe they'll go for it?

Models are a terrible idea. It'll all look fake and amateurish.

They won't. For one thing, why should they give away licensing rights? For another, they don't need to "pay" anyone with free footage for ideas, they have staff for that.