X happened to Y, which is more than can be said for Z
This could be paraphrased as:
X happened to Y, but the opposite is true for Z
Here's an example from a discussion board:
You didn’t overdose on turkey, Christmas pudding, mince pies, brandy butter, Brussels sprouts or any of the other staples of a typical yuletide. Sadly, that’s more than can be said for the retailers, supermarkets, and chains.
This means that you didn't buy too much food – but the stores did. (The writer is alluding to how stores bought much more than they sold in the Christmas season, and now they have excess inventory to deal with.)
Another example, from a film review:
She penned something that gets people talking about her theme of unconditional love, which is more than can be said for many screenwriters.
This is saying that most screenwriters have a hard time getting people to talk about the theme of unconditional love, but she (the subject of the sentence) managed to pull it off.
Now, to the example you found:
He was unhurt, which is more than can be said for the car and the police station.
In other words, "He was unhurt, but the opposite is true for the car and the police station." I would interpret that to mean that the car and police station sustained a lot of damage.
It should be noted that this is a somewhat wry, informal expression; it makes the point by adding a touch of irony, surprise, or subtle humor.