SSRS - Matrix table with grouping, but merged data value

I have a matrix table in SSRS Report Builder that I want to make a few changes to. I have multiple rows side by side: Customer, Vehicle and Postcode, with Date as my columns and Value as my data. Currently, I get an individual value for each Customer, Vehicle and Postcode per date, however I want a sum of the Value for each customer overall (per date), whilst also being able to have full view of the vehicle and postcode split.

See below for sample data and my desired end result which will probably help explain my problem a little better.

[Sample Data]

[Desired End Result]

Thank you for any help :)

I don't think this is possible with a matrix without jumping thru hoops (even then I'm not sure it'll exactly what you want). You might need to consider a different layout showing details and have a total for each customer by adding a total to the vehicle row group.

In this example there are three row groups, one for each of Customer, Vehicle and Postcode, with a total added before vehicle.

As a side note, when posting questions, please post sample data as text or better still, a script to generate the data.