Fact : JPJ does not allow Singapore, Thailand and Brunei scrap cars to run on Malaysian roads
In Singapore, anyone who owns a car requires a COE (Certificate of Entitlement), the price of the COE can go as high as the car itself and the tenure is 10 years. After 10 years, the Singaporean car owner who does not want to renew their car's COE might scrap the car.
There are a few Facebook advertisements on purchasing Singapore scrap cars. All (read again) of these advertisements are scams.
The ad shown below is a seller selling a Toyota Estima at RM20,000 only with the catch as coming from Singapore as a scrap car.
Malaysia’s JPJ does not allow used of scrap cars from Singapore and neighboring countries in Asean (eg Thailand and Brunei also). This is illegal and even if the car could be brought into Malaysia, it is not even legal to drive it and car owners can get jailed for it. The Singapore scrap car that is successfully brought into Malaysia needs to use fake insurance, plates and road tax to run on Malaysia roads (read: illegally). In addition, buying the scrap car from Singapore for the use of repurposing the car for spare parts is also illegal but some car workshops have been known to do so.
Having said this also, cars from Japan is permitted to be imported. Don't let greed take over logic.