Looking to upgrade daily driver

I would like to bounce a few ideas here
I am looking to upgrade my daily driver it must be the following
1) a four door saloon
2) a diesel
My current daily driver is 2.0 2007 volvo s40 a good car but a tad thirsty and the car tax is quite expensive.
So my ideas so far are
1) just a newer diesel version of what I have
2) I quite fancy a C class I would probably go for the 220 CDI anyone have one? or recomment it?
Any suggestions welcome what would you do?
I am looking to upgrade my daily driver it must be the following
1) a four door saloon
2) a diesel


My current daily driver is 2.0 2007 volvo s40 a good car but a tad thirsty and the car tax is quite expensive.
So my ideas so far are
1) just a newer diesel version of what I have
2) I quite fancy a C class I would probably go for the 220 CDI anyone have one? or recomment it?
Any suggestions welcome what would you do?