The passenger vehicle industry had projected a YoY growth of 19.6% (source); the registrations have actually declined by -7.12% in Aug’20 v/s Aug’19.
OEM wise Passenger Cars Market Share Data for Aug-20 with YoY comparison –

Source: FADA Research
Maruti Suzuki reported an increase in Market Share YoY and was able to command a Market Share of ~50% in August 2020.
Hyundai ranked second and recorded a Market Share increase too.
Tata had an impressive month where both Wholesale & Retails were better. It also increased its Market Share by 2.3% in Aug’20 v/s Aug’19
Mahindra’s Market Share loss was the highest in August 2020. The Indian major’s market share dropped by -2.7% in Aug’20 v/s same period last year.
Kia is on a roll. It is already commanding a Market Share of 4-5.% within 1 year of operations. With Sonet; Kia is surely eyeing Mahindra’s & Tata’s spot.
While MG recorded a YoY growth of 41.3% in terms of wholesales; the registrations surprisingly recorded a degrowth of -8.9%.
Disclaimer: 1- The above numbers do not have figures from AP, AN, MP, LD & TS as all these States/UT’s are not yet on Vahan 4. 2- Vehicle Registration Data has been collated as on 07.08.20 and in collaboration with Ministry of Road Transport & Highways, Government of India and has been gathered from 1,235 out of 1,445 RTOs.