The West Midlands Mayor said new 'Rules of Origin' included in the agreement will encourage car makers to use more British-made parts – potentially boosting jobs across the region.
Under the rules, products built in the UK must have a minimum amount of their parts made either here or in the EU to count as British when it comes to exporting.
Conservative Mayor Mr Street says the change offers a huge opportunity to expand the local supply chain for our biggest manufacturing industry.
He said: "As in many manufacturing sectors, in recent decades much of our automotive supply chain has, regrettably, moved from the West Midlands to Asia and the rest of the world, taking with it quality jobs.
“Now, as a result of the EU trade deal, the automotive industry and others has a driving imperative to source more parts and components from the UK – or face tariffs that will make its exports uncompetitive in our biggest trading partner.
“This amounts to a big opportunity for the West Midlands in the small print of the EU trade deal."
The threshold for British-made parts starts at 40 per cent but will rapidly reach 55 per cent as a minimum, which Mr Street says creates "huge scope and opportunity to rebuild and expand our automotive supply chain".
He said growth to the region's significant supply chain around car making would lead to more jobs.
“We are well placed to take advantage of the trade deal and grow this eco system of suppliers,” he said.
“While the days when almost every car part was made locally are a distant memory, we now have a real chance to bring some of these jobs and plants back from Asia to the West Midlands.”
Mr Street also renewed his call for a 'gigafactory' to be built in the West Midlands, to make the batteries needed for electric motors.
He said: “The highest value parts in any electric car will be the batteries that power it. So, ensuring our own ability to build these car batteries at scale in this country is critical.
"That means gigafactories, like the one built by Tesla in Nevada.
“The Government has recognised this by allocating £500million towards this technology. Here, in the West Midlands, £108million has already been invested in a Battery Industrialisation Centre.
“A gigafactory, and the supply chain that would gravitate around it, will make a huge contribution to meeting the need for British-built parts in our cars. It will be vital not just future jobs, but for keeping the ones we have.”