Britney Spears' son drives mother's convertible after her DUI arrest... before shopping with bikini-clad girlfriend

Britney Spears's son Jayden Federline was seen taking a spin in his mother's luxury convertible - a week after she was arrested on suspicion of DUI.

Jayden departed his mother's Thousand Oaks home in her sporty Mercedes-Benz car earlier this month, his eyes on the road as he enjoyed a solo drive through the quiet area. 

The following day, Jayden had company when he stopped by the trendy health-food store Erewhon.

The 19-year-old was joined by his girlfriend as they browsed through the popular spot in neighboring Calabasas. 

The duo appeared to be waiting in line for food before Jayden's girlfriend, clad in a bikini top and sweatpants, left the store with one of their nourishing smoothies. 

Spears has Jayden as well as Sean Preston, 20, with her ex-husband Kevin Federline, with whom she was married from 2004 until their divorce in 2007. 

Spears was arrested on suspicion of DUI on March 4 in Ventura County by the California Highway Patrol. She was released the following morning.

Representatives for Spears later released a statement in response to the arrest to the Daily Mail, which read: 'This was an unfortunate incident that is completely inexcusable.

'Britney is going to take the right steps and comply with the law and hopefully this can be the first step in long overdue change that needs to occur in Britney's life.'

They added, 'Hopefully, she can get the help and support she needs during this difficult time.

'Her boys are going to be spending time with her. Her loved ones are going to come up with an overdue, needed plan to set her up for success for well-being.'

Dispatchers and officers could be heard during a 911 call as they described the incident as it took place in real time.

A dispatcher stated, 'A black sedan, erratic braking, swerving and driving with no taillight.'

One officer then requested, 'Can we send all units down towards this area please?' The vehicle was later identified as a '2026 black BMW convertible.'

The call initially began around 8.13pm and dispatch confirmed an hour later that the 'driver is out of the vehicle.'

Police reportedly found Adderall inside her vehicle and the pills were being tested to determine if they were pure Adderall or laced with other substances.

If the substance tests positive for a narcotic, Spears could possibly be looking at jail time.

But if it turns out that narcotics were not involved, then the pop star will not face jail time, Los Angeles-based attorney Tre Lovell told the Daily Mail.

It is also not yet known or confirmed that the singer had been under the influence at the time of the incident.

The star's former personal assistant and longtime pal Sean Phillips also spoke on Spears' behalf during an appearance on TV show Good Morning Britain, saying she was 'okay.'

'She is such a great person and we all make mistakes,' Phillips expressed.

'It makes me feel bad when she suffers such public mistakes. I want the world to know she's a great person...We all make mistakes.'

Phillips added that he would like to see the songstress move away from Los Angeles before sharing that the star is the 'same Britney that I knew in 2003.'

'There is no dissociation with her that I have with her character and personality,' he continued.

Phillips then shared, 'You have to think about who else she is associating herself with' - but did not go into further detail.

Others close to Spears have spoken out since her arrest, including exes Sam Asghari and Federline.