The Motor Trade Association is accusing local councils of turning a blind eye to the increasing number of organised roadside car sales, which it says can provide a venue for illegal sellers and cars riddled with problems.
MTA's web and communications manager Ana Zandi said today it was not opposed to people legitimately selling their own vehicles privately outside their homes.
"However, we are concerned that some traders are masquerading as private sellers to avoid their financial and legal liabilities and, thereby, also reducing the buyer's legal rights."
Ms Zandi said the concept of roadside selling did not support the local business community which was meeting its obligations in paying taxes and rates, and complying with relevant local bylaws.
"Local businesses employ local people and invest in our communities, so it's unclear why local councils endorse street trading."
She said MTA had received many complaints from people caught out after buying a vehicle from these roadside sales venues.
"In most cases, the buyer has little scope for redress and is left with a problem vehicle."