For car finance from bank, following some points should be considered.
1. KIBOR (today is apx 8 yearly basis).
2. Which bank has lowest KIBOR plus offer. (for salaried person and businessman this offer is diff). It means some banks offer KIBOR plus 2%, some banks offer KIBOR plus 2.5% or 3% etc.
3. Installment will vary every six month or yearly depending upon bank and KIBOR (instalment may increase if KIBOR increased as per bank policy).
4. Insurance policy plus tracker charges. Every bank has diff policy. Some at 2.5 % of value and some more than this or less than this.
5. If u consider insurance and tracker useless in ur area, then it is my advice no to go for bank finance as u have to pay much extra amount in form of processing charges, and interest rate (huge amount will be paid to tracker and insurance company also which will be included in installment). As u have 60% amount, so its better to get loan instead of car financing.
If u will opt for tracker and insurance also, then finance from bank is feasible.
6. WHT is paid by Bank islami if u lease from BIPL ( may be by some other islamic banks also but not by conventional banks).