Red-shirt leader Nuttawut Saikuar will lead a parade of vehicles on Aug 29 to keep up the pressure on Prime Minister Prayut Chan-o-cha to resign.
Mr Nuttawat announced the new date of the car mob rally on his Facebook on Thursday.
The first convoy on Sunday organised by him drew thousands of vehicles in Bangkok and other provinces but the peaceful car rally was marred later in the evening by a clash between young demonstrators and police at Din Daeng intersection.
Mr Nuttawut avoided politically sensitive places including Government House and the residence of the prime minister in the rally last Sunday.
He has been ordered to meet police at Lumpini station to be informed of a charge of organising an activity that could put people at risk of being infected with Covid-19.
Daily rallies have been held in Bangkok demanding that Gen Prayut step down for mismanaging the Covid-19 situation.
The Tha Lu Fah group held a rally at the Democracy Monument on Thursday for three hours to 7pm to avoid confrontation with approaching riot police
