A driver who allegedly had a blood alcohol content four times the legal limit has lost his licence after an Adelaide police patrol noticed a rose bush embedded in his car.

Key points: The 21-year-old driver allegedly returned a reading of 0.209

The 21-year-old driver allegedly returned a reading of 0.209 He has lost his licence for a year and has had his car impounded

He has lost his licence for a year and has had his car impounded A Coober Pedy man was also charged after allegedly attempting to avoid a coronavirus checkpoint

The man's car was spotted on North East Road at Holden Hill about 2:30am travelling north with its lights on high beam.

Police followed the car and then noticed what they described as a "large ornamental rose bush" attached to the left side of the car.

The car was then pulled over and the driver was breath tested.

The 21-year-old from nearby Klemzig allegedly returned a reading of 0.209, more than four times the legal limit.

He was reported for drink driving, lost his licence for 12 months and had his car impounded.

"Police were unable to locate where the rose bush came from and have left it near bus stop 23, North East Road," SA Police said.

Last night, a 45-year-old Coober Pedy man who was allegedly more than six times the legal limit tried to steer clear of one of the state's coronavirus border checkpoints, police said.

The man allegedly tried to avoid the Marla Border Check Point in the state's far north by driving to a nearby service station about 8:10pm.

"Police approached the car and directed the driver to stop before submitting him to a breath test … [he] returned a positive result of 0.316," police said.

The man was charged with drink driving and driving while disqualified.

Hours later, another alleged drink driver was reported after he was breath-tested at Murray Bridge.

The 50-year-old local man allegedly returned a reading of 0.198 and has lost his licence and had his car impounded.