Gavin Reid-Honeyghan took no notice of Dilip Singh Verdi’s repeated calls for help and later claimed the car he had been driving was stolen.
Mr Verdi, a 45-year-old baker, suffered a ruptured spleen, a collapsed lung and fractures to his ribs and vertebrae.
He also has psychological problems and will have to take medication for the rest of his life following the incident in Hockley.
Birmingham Crown Court Judge Patrick Thomas QC told Reid-Honeyghan he had ruined Mr Verdi’s life and described his behaviour after the accident as “both deliberate and disgraceful.”
Reid-Honeyghan, 25, of Jacey Road, Edgbaston, admitted causing serious injury by dangerous driving and failing to report an accident. He was jailed for two years and eight months and banned from the roads for two years.
Matthew Barnes, prosecuting, said the incident happened as Mr Verdi was driving to work on May 5 in Benson Road, in Hockley.
He was at a mini roundabout at the junction with Park Road when he was struck hard by a VW Golf driven by Reid-Honeyghan. It was estimated he had been driving at around 50mph.
According to Mr Verdi, three men got out of the Golf and began walking around his vehicle and he called out for help three times. The victim said some of the group then looked into his glove box and he thought they were going to steal something.
After a few minutes the defendant and his friends were collected by another vehicle.
The vehicle that had collected the men drove off but returned shortly afterwards when one of the group collected something from the wrecked Golf before going off again.
Mr Barnes said passers-by did eventually come to Mr Verdi’s assistance. He was taken to hospital where he had his spleen removed and spent nine days being treated. He said the Golf had belonged to Reid-Honeyghan’s girlfriend who, at his prompting, had reported the car stolen.
Babir Adris, defending, said Reid-Honeyghan could remember little of what happened after the collision.