I don't know of any new cars that have 10W40 as the recommended fill.
However, I do know that many cars in Australia are running on 10W40 Semi-Synthetic right now. Here it's the default bulk fill for many shops and garages, my local one included. They all seem to use a semi-synthetic 10W40 that is both API SN and ACEA A3/B4.
I assume it became so common because it was the one grade that worked for most applications. It was A3/B4 for the Euro cars, it was SN for the Japanese cars, and many local cars spec'd a 15W40 mineral - so it worked for these Holden's and Ford's too.
Met a guy with a 2005 Corolla with the 1ZZ-FE engine, he said the Aust. owners manual spec'd 10W40, and one of our first Castrol Magnatec grades was in 10W40, so it's a common oil around here.
In my personal oil stash, I have 6L of Penrite Vantage, 5L of Valvoline DuraBlend and 5L of Shell Helix HX7 all in 10W40 semi-syn with SN and A3/B4.
They are quite affordable (for Australia), I've picked them up at $20 to $25 for 5L on sale, and most carry a few Euro OEM spec's too, such as the Shell Helix HX7 below
Quote:
Specifications: API SN/CF; ACEA A3/B3, A3/B4; JASO SG+; MB approval 229.3; VW 502 00/505 00; Renault RN0700, RN0710. Meets the requirements of Fiat 955535-G2