What`s the credit limit of your card? If you can pay up the money upfront (instead of EMIs) some dealers used to give good discount 5-6 years back. I do not know about India, but here in Europe you will get some points/ something like that which can be used during hotel/ flight bookings etc. (mostly of no use)
Why not just pay upfront?
I`m slightly baffled by the question. Never heard of anyone buying a car with CC.
If you can pay a credit card bill of 8 lakh in a single month, why not transfer the money directly upfront? EMI on CC will cost you a lot more.