Will a back box change the sound of a diesel car?

It probably will, but not for the better. Chav exhausts and Dizzlers don't go together.

Don't know why people convince themselves that altering the exhaust and possibly invalidating insurance will make a tin can sound any better, if you want a good sound then a V8 or six pot but a four pot? That goes for petrol as well.

Save your money and only replace the system if it is faulty, put the money to a holiday or treat your self, or just sound maintenance on the car, the car is just a money pit unless you can afford luxury models.

Not a lot will happen, as another poster said it will sound like a truck and possibly get the attention of Mr Plod, you drive a diesel live with it its never going to sound like a GTI.

I did the same with my 2.0 rover 200 and with the decat on too it was a much deeper rumble i thought it sounded good look on youtube

It's a diesel and will always sound like a dumper truck.

Get over it.

might do slightly, thats providing someone makes a diesel sports backbox.

only one way to find out ! search online, and get it fitted .