As well as working as an engineer, "Warren" works as a part-time courier, delivering cakes, sandwiches and coffee in his Toyota Wish before and after work - and even during his lunch hour.
The 30-year-old signed up to on-demand delivery service CarPal three months ago and earns between $250 and $500 a week in extra income.
Warren (not his real name) told The Sunday Times: "I like to drive and I can use the car to generate income rather than wasting time at home."
CarPal and its larger competitor RocketUncle are among a host of on-demand delivery start-ups to have sprouted up in Singapore over the past year.
They use apps and websites to link their clients with third-party drivers - much like how taxi booking apps match passengers and cabbies.
But while firms like Easy Van and GoGoVan prefer their drivers to have a lorry, van, or motorcycle, CarPal and RocketUncle also target regular car owners who may have little experience in logistics.
CarPal founder Maarten Hemmes said 80 per cent of its 150 registered drivers belong to this demographic. They range from cabbies and Uber drivers, to real estate and sales agents, and others who want to make extra income on the weekends or evenings.
"The idea is that when you are going from point A to B for your work or any other reason, why not take a package along? From a couple of cars in a courier company's fleet, we are expanding our resources to millions of people who have a vehicle."
The Dutchman launched CarPal here last May. About eight in 10 of his orders involve perishables and fresh items, likes flowers, cakes, juices and food.
RocketUncle, which launched here in January last year, has almost 5,000 drivers - about half of them car owners.
Founder Noam Berda said most are shift workers with extra time on their hands.
Each earns $5 to $15 per package delivered depending on its size. RocketUncle now handles an average of 3,000 deliveries a day, mostly documents from offices and parcels from shops. It has even helped hair salons deliver shampoo to customers who want to buy an extra bottle.
"Every job has a price and location - drivers can then decide if they want to fulfil them," said Mr Berda, a 39-year-old Singapore permanent resident.
He added that all its drivers are screened and are either Singaporeans or Singapore residents.
A driver can also be locked out of the system if his or her performance is not up to par.
RocketUncle will launch in Manila next month.
One of its drivers, who wanted to be identified only as Mustaqim, said he does up to 10 jobs a day in his Mitsubishi Lancer. The 33-year-old sales agent juggles the work in between meeting clients.
After discounting his petrol costs, he can earn about $40 to $50 a day.
Mr Zayed Talib, from online shawl retailer Adlina Anis, has been using RocketUncle since last June. His company used to have two delivery drivers on its payroll, but let them go because "it was too expensive". He and other colleagues then started doing deliveries themselves but ran into problems with consolidating orders.
"We were tied up with meetings and it was difficult because the delivery information was not housed in one place," he said, adding that RocketUncle handles about 20 same-day deliveries for his company every day - a service that costs about $1,000 a month. "That's cheaper than hiring drivers, who sit around doing nothing between deliveries. If they didn't turn up for work, it was a huge blow to operations."
But while doing deliveries can help some make a quick buck, General Insurance Association of Singapore executive director Derek Teo said that under a private car motor insurance policy, the use is restricted to "social, domestic and pleasure only".
If the vehicle is used otherwise and the driver has an accident, the insurer is likely to decline liability since there is a breach of policy condition.
Mr Teo said: "If the driver had used the vehicle for a paid delivery, it is clear that he is discharging a commercial transaction, which would mean the vehicle had been used for business purposes."
Both RocketUncle and CarPal advise their drivers to check with insurance providers about coverage. Both companies cover goods delivered by up to $500 and $250 respectively, in the event they are damaged or lost.
Meanwhile, GoGoVan's country manager for Singapore, Mr William Ban, said his firm is not ruling out using car drivers. "Depending on the market demand in (the) future, we foresee other types of transportation may also play a role in this space, such as sedans, bicycles and even on foot!"
Traditional courier firms such as ixpress647, which has been around for four years, said its business has not been affected by the new start-ups.
Owner Aznan Zainal, 29, said: "I do more contract services, rather than ad-hoc orders. The items can be worth a few thousand. From a business perspective, they will not want a random person coming to pick up their goods. We arrange the deliveries and have full control over our drivers."