Here's my two cents mate.
I just cancelled my order on a new 1.2 TSI Polo with VW, a £2000 deposit and £300 a month, free insurance, free tax (£95 after first year) and free servicing for 3 years. Seemed like a really good deal.
I agreed and started the ball rolling. Bare in mind that I live with my girlfriend and we rent a place, pay food etc. so I knew all this beforehand. But when I thought about it properly, it was over £12,000 in 3 years and I wouldn't even own the car. That's a lot of money.
I could do so much with that money and that's now exactly what I'm doing. We are now going on holiday next month. I know I have money left over each month that can be used for whatever I want.
Just think about it properly.