Back to the car v house thing, if you want the car and you can afford it, I'd go for the car now.
If you have a reasonable income and few outgoings, you should be able to save, or if you have finance, have it over a short period to get the car paid for as soon as poss. Once you own the car, apart from the running costs that you would have with any car, that's it. It's yours.

But you will need to keep it, then start saving for your house.
If you keep the car, depreciation dosn't really come into the equation. You only realise the loss when you cash it in. Look after it, maintain it, keep it clean and the right way up and you'll still have a nice car in a few years time when your buying your house.
In time it will be a really sought after car. One owner, full history etc. Once it gets do about 5 years old, I'd be tempted to buy a cheap daily car, and keep the Golf for weekends and special occasions. That'll keep the mileage down, and even when you are driving your dull daily, it's a nice feeling knowing that you have something nice tucked away at home.