It is a bad title. I assumed it to mean % of cars sold in China which counted as US built, as you might get an idea of from comparing company's Chinese manufacturing figures with their Chinese sales figures and looking at what they export from the US.
Top Brands (Sales)
Passenger Vehicles
# Brand Jun YTD YTDShare
1 Volkswagen 236,715 -8% 1,431,398 -8% 14%
2 Honda 137,212 13% 758,494 14% 7%
3 Toyota 130,678 16% 730,761 13% 7%
4 Nissan 102,147 -1% 550,008 -1% 5%
5 Geely 80,477 -32% 591,668 -18% 6%
6 Buick 69,856 -5% 439,322 -15% 4%
7 Changan 67,435 4% 378,184 -22% 4%
8 Hyundai 63,079 -28% 319,424 -16% 3%
9 Mercedes-Benz 59,351 2% 359,970 3% 3%
10 Audi 59,012 29% 294,301 -7% 3%
11 BMW 55,265 24% 345,561 20% 3%
12 Chevrolet 49,386 -6% 280,481 -15% 3%
13 Beijing 47,855 4% 163,134 -36% 2%
14 Haval 45,256 7% 352,872 8% 3%
15 Trumpchi 44,124 19% 186,947 -30% 2%
16 BYD 38,013 3% 223,180 1% 2%
17 Baojun 35,735 -43% 249,576 -47% 2%
18 Chery 34,658 -1% 190,154 -9% 2%
19 Dongfeng 32,874 25% 170,355 -33% 2%
20 Roewe 30,727 -18% 204,494 -15% 2%
PV Total 1,829,042 -4% 10,519,059 -13% 87%
Commercial Vehicles
# Brand Jun YTD YTDShare
1 Wuling 45,488 -34% 315,728 -7% 20%
2 Foton 34,080 4% 201,892 11% 13%
3 Changan 22,617 -36% 160,283 -17% 10%
4 Dongfeng 19,284 -10% 137,334 0% 9%
5 Jinbei 12,132 8% 68,476 3% 4%
6 JMC 11,945 -44% 75,045 -20% 5%
7 JAC 9,956 -24% 108,872 -5% 7%
8 Great Wall 7,166 -19% 64,878 0% 4%
9 Isuzu 6,865 -17% 33,599 -5% 2%
10 Maxus 6,309 -28% 39,346 -20% 2%
CV Total 231,047 -24% 1,606,503 -5% 13%
Top Manufactures (Production)
# Manufacturer Jun YTD YTDShare
Passenger Vehicle
1 Volkswagen 236,963 -15% 1,393,650 -10% 13%
2 Honda 136,242 -2% 742,231 3% 7%
3 Toyota 120,560 8% 657,619 12% 6%
4 Nissan 91,749 -15% 557,100 0% 5%
5 Geely 81,219 -37% 596,201 -15% 6%
6 Buick 73,562 -1% 422,355 -17% 4%
7 Changan 59,566 8% 398,705 -10% 4%
8 Chevrolet 50,744 6% 279,651 -15% 3%
9 Beijing 44,926 16% 162,518 -33% 2%
10 Haval 44,437 7% 352,403 10% 3%
11 Mercedes-Benz 43,843 3% 283,771 14% 3%
12 Audi 42,894 -21% 266,973 -13% 3%
13 BMW 36,783 20% 245,001 16% 2%
14 Chery 36,101 -4% 191,141 -8% 2%
15 Hyundai 35,300 -53% 314,000 -16% 3%
16 Roewe 34,250 -17% 194,612 -25% 2%
17 BYD 33,087 -13% 217,449 -3% 2%
18 Dongfeng 26,878 20% 157,267 -37% 1%
19 Baojun 23,461 -64% 248,207 -52% 2%
20 Skoda 22,832 -45% 110,862 -43% 1%
CV Total1,577,781 -17% 9,796,935 -16% 86%
Commercial Vehicle
1 Wuling 41,249 -15% 319,550 5% 20%
2 Foton 32,718 2% 203,352 13% 13%
3 Dongfeng 19,193 -9% 132,873 -4% 8%
4 Changan 17,463 -48% 155,291 -11% 10%
5 Jinbei 13,612 11% 71,631 9% 4%
6 JMC 11,019 -45% 71,978 -23% 4%
7 JAC 9,690 -26% 106,732 -1% 7%
8 Great Wall 7,452 -18% 66,784 -3% 4%
9 Maxus 6,387 -25% 38,361 -20% 2%
10 Ford 5,536 -39% 34,443 -20% 2%
PV Total 211,953 -23% 1,592,937 -1% 14%
-https://lmc-auto.com/wp-content/uploads/2019/07/LMCA-China-Light-Vehicle-Sales-Update-July-2019.pdf
The figures for % cars sold in China which count as US built aren't necessarily going to be stable though as companies adjust to limit their exposure to Trump's trade war, for instance:
). He’s delighted to be able to overtake an elderly Vauxhall Nova and a Honda Accord 
.