I think there are so many advices that confusing you.
To simplify what they talked about:-
1. Your interest rate is 3.5% which is not amortized. This is equavailent to effective rate of 7.x% as described by one of the forumer. Meaning, this is equal to 7.x% Fixed Deposit interest rate. The current FD rate is 2.5%.

2. Do you know settle you car loan earlier you can save interest? Let say u take 5 year loan and now you at 3rd year. if you settle it at 3rd year, they will fine you 1 year interest and deduct the last year interest for you. Check out the $ you can save from Hong Leong website. https://www.ecloan.com.my/calculator/loan_settlement.asp. You should negotiate with the bank regarding the fine. Anything under the sun can be discussed.

3. In order for you truely get the benefit, you need to get an investment higher than 7.x %/year + the fine if you want to reap the benefit of keeping the money.

4. If you are a person that dun like debts, you shd pay it off to clear your mind.

5. If you have an investment that can yield more than 7% and potentially go higher in future, keep the money.