No I don't think that's right, see below :I believe GM sold only 440K Buicks, the rest were Chevrolets, Wulings, Sabres etc.
VW is larger in China than GM. GM uses a clever PR trick - by production/sales volume, SAIC-GM is indeed number one in China (OK, was until lat year), but VW has TWO JVs, SAIC-VW and FAW-VW, which are both comparable in size to SAIC-GM and thus combined VW production/sales in China is higher.
VW sold a total of 910,000 in China in 2007 (all ventures), GM a total of 1.03 million. But the big story is Toyota up 62% to 500,000.
I think the confusion around GM is that half of their sales are Wulings - tiny vans made my a company that until recently GM only had a minority shareholding in. So Toyota and VW are both outselling GM in terms of "real" cars.