DBS and Esso recently held a promotion to give-away a free Porsche 911 (1st Gen) car model (limited stock run) for every $300 & above spent on Supreme+ (aka Esso 8000 grade) petrol with DBS-Esso card from June 19 onwards.
The car model is pretty good in build quality considering it's a free gift and the DIY installation is pretty straight forward as well. The box comes with the tools required to install the car model (which essentially is a screw driver to join the top and bottom of the car). It's a limited stock run so do take note that it's may not be available throughout.
If you want this, you can probably still get it in some Esso station. Be sure to keep the receipts to qualify for this free exchange.