The authors have sufficiently addressed the review comments though some revision is still necessary to add missing citations and also to improve the written English.

The responses address the referee comments sufficiently and this manuscript should now be published. I do suggest that the authors add a discussion of how the findings in this work relate to the model findings in Zhao et al (SciRep 2016), who found that accounting for semi-volatile POA and IVOC emissions from vehicles in a version on CMAQ including the 2D-VBS led to a large enhancement in the modeled SOA and significant improvements in model-measurement agreement for Eastern China. However, as I am a co-author on that paper I also emphasize that this is a suggestion and in no way a requirement.

Zhao, B. et al. Quantifying the e ect of organic aerosol aging and intermediate- volatility emissions on regional-scale aerosol pollution in China. Sci. Rep. 6, 28815; doi: 10.1038/srep28815 (2016).

Add an indefinite article and this is good to go:
line 286: "2D-VBS box model, a previous study"