I'm a salesman myself.
For this example, I'll assume a RM50,000 car that you'll be buying.
Bank Negara laws prohibit banks from doing full loan (100%) for customers. Full loan here means 0% downpayment, a.k.a you don't have to pay a single cent and drive the car off the dealer.
2 banks in Malaysia, however, are exempted from this law. One is Bank Rakyat, which, under the right circumstances, offers true full loan. Another bank is Bank Islam, via the graduation scheme (meant for fresh grads).
So some customers wouldn't want (or rather, can't afford) to pay the required 10% downpayment. On paper, if the car price is RM50k, and the dealer submit a loan request of RM50k to the bank, it will be rejected almost right away.
Here's where the "trick" comes in. The principle is simple. Mark up the price of the car.
So, back to the RM50k car. To get around this problem, the dealer will add in several optional extras into the Vehicle Sales Order (VSO) form, such as accessories and bodykits. The purpose is to make the car even pricier, say RM59k.
Now the price is RM59k, an extra 9k. But the dealer will still submit the loan request to the bank of RM50k, because that's the actual price of the car. The extra 9k is just for show to the bank. You are not supposed to pay that extra 9k.
Your loan should be much easier to pass now, because in the bank's eyes, you're buying a RM59k car and requesting a RM50k loan, meaning you have "put down" a downpayment of 9k. But in reality, you didn't.
HOWEVER (big one), the added accessories will incur additional GST charges to your final car price. But this typically won't exceed RM1k, depending on the car you buy . And, depending on your documents, some banks won't even allow you to have RM50k loan. That all depends on your credit score.
You might be asking, "do they have to do all this if I pay an actual downpayment to my car?" The answer is a definitive no. But it has to be at least 10% of the total car price. If you are paying the downpayment already and still your dealer wants to markup the price, then something fishy is definitely going on. It could be meeting loan sales target, just saying. But you as the customer have the full rights to question them about it.
Let me know if you need anything. I'd be more than happy to help. Good day!