There are two points.
1- when you make full payment at the time of booking you become eligible for claiming "Interest" which Honda earns on your deposited amount if your delivery is after 2 months. According to new auto policy car manufacturers are bound to deliver booked car within 2 month. If they deliver it after 2 months then you can claim interest from 61st day till delivery date. Since Honda is taking 6 months to deliver cars so you can earn around 30-40k(not 100% sure) for 4 months late delivery.
2- when you book car by paying minimum amount then you are keeping yourself on safe side. You have your money in your hand. You can use it whenever you want. You are not at the mercy of Honda.
For example book Honda City by paying 9 lac and keep 8 lac in your hand to pay them near delivery date. Your 8 lac are your peace of mind. You can even buy a second hand car in case of emergency if delivery is delayed by 3-4 more months.
I personally think option-2 is a better option. I made this mistake in February by booking car with full payment. My delivery date is in July and I am carless since that day. If I had that amount I could have bought second hand car. Secondly I lost interest amount also because Honda increased the price in April and didn't inform me. I was shocked to hear when on 6th June dealership called me for remaining amount to confirm booking though I paid full amount at the time of booking. Hence I lost around 20k.
Lesson of the day: Never pay full amount to anyone if there is an option to pay minimum amount. It applies to any kind of business.