How big is the lip on a +30 offset?

19X9.5 +30 with 1" drop = rubbing?

what? I don't think the lip is dependent on the offset? Unless you are talking about how much the wheel sticks out? In that case, at +30 offset, your wheels will not stick out, and not only that, it WILL be sunken battle ship. However, I think don't think 19X9.5 +30 with 1" drop would rub. If you want your wheels to stick out, I would suggestive +20 with little to no fender rolling, +22 would be perfect.

I've read up on offset, but I still don't really understand it.

I mean, doesn't a rim have to have a low or negative offset to have a wider lip?

The lip isn't really my main concern. I want flush. Volk GTS' unfortunately skip 18x9.5 and go directly to 18x10 and has offsets of +15, +27, and +33.

The 19x9.5 has +17 and +30. I assume that +17 would require a lot of fender rolling. What's the real difference between +17 and +30?

18x10 +15 +30 will not be flush +17 will need rolls but will probably be pretty hot lol

I think it's time for an offset faq

^^yes please do