Subtotal withou taxes including shipping and coupon

Hello,
I searched for a solution but I can´t find it.
Now is Subtotal in cart just sum of prices of the products.
But we need the Subtotal including shipping and coupon.

for example:
1. product cost $100 without tax
2. product cost $30 without tax
shipping cost $20 without tax

Subtotal - $130
Taxes 19% - $31.5
Total - $181.5

In one look is customer confused cos $130 + $31.5 isn´t equal $181.5.

Is there a way how to include shipping and coupon to this subtotal so in this case would be like:
Subtotal - $150
Taxes 19% - $31.5
Total - $181.5

Thank you.

That would require a new total extension to be built rather then editting the current subtotal.
The current subtotal could be renamed 'products' and it should have the same sort order (first) then come any other totals and then you could add this newly created total right before tax. The number reported in this total should be a sum of all previous totals.
I know this isnt a ready solution but perhaps it'll help you.

Thanks for the advice. Unfortunately, I don´t have enough experience to do that. If somebody have some solution or maybe some extesnion, I would appritiate.

I have an extension I've been working on that lets you get an intermediate sub-total like this. It's nearly finished, so I'll post here when it's done and available.

Perfect. Thanks.

I've now finished the extension and released it:

Intermediate Order Total

It does require that the usual Sub-Total line item be active (so that the totals get added properly) but if you want to hide that line item, I can give you a code edit to do that on the front-end, as long as you're not using a quick checkout.

Feel free to take a look at the screenshots and demo site, and if you're interested let me know at www.getclearthinking.com/contact if you have any further questions.