My grandmother would always add some kind of smokey German type of sausage to her cabbage soup or a smoked pork chop with the bone. Gives it a great flavor as sometimes just plain cabbage soup can be a bit boring in flavor depending on your palette.
I haven't made cabbage soup with a bone like the recipe calls for, but I have used V8 Spicy, just to give it a little extra character! It's a good result.
They also make vegetable stock instead of chicken or beef stock. I've seen it in the supermarket. I've never tried it, but I have friends who are vegetarians who use it for vegetable barley soups and the like. It's a bit bland for my tastes, but I think Diane has the right idea of using a spicy version of V8 for some kick.
I may try that. V8 as a sports drink is a little expensive. I am used to it being in a can but now they have them in bottle for upwards of $3.00 where its cheaper to buy the canned vegetables or a no name brand juice.
I chuck v8 in soup quite often, but I personally prefer my cabbage / onion / potato type soups with a broth / cream base, and my bean / vegetable kind of soups with a tomato base. I just think the tomato tends to overpower cabbage soup.
Spicy v8 is a great boon in general though! I just made a red beans and rice sort of concoction that involved a v8, some andouille sausage, garlic, and a roux. I also roast chicken thighs with v8 and Wicker's BBQ sauce, it's my go-to express meal for when I really feel lazy. Perfect tender chicken that seems like you took a lot of trouble, and the only skill required is pouring.