This is suicidal. Car park are also real estates and can fetch rental too. At RM40k, to get a 5% ROI, would need to rent it at RM170/month.
Or if you calculate the psf rate, its RM330psf. (A condo's carpark size is roughly 120 sqft).
That's just for a empty bare piece of property with cement finishing.

For comparison, I bought a condo in Puchong, in 2011, at around RM400k, additional car park only RM15k.
Car park for new project nowadays go for RM18k-RM30k, depending on location. RM30k would be those at very good locations, certainly not Selayang.

New condo projects in Cheras, additional car park is around RM20k-RM25k.