What all things do I need to check before buying the car insurance policy?

I have bought a Maruti Alto last year and now I am heading for a renewal of my car insurance. Last year, it was insured by National Insurance. This year I am getting various calls from lots of provider and I have finalise two provider (National Insurance and Bajaj Allianz) on the basis of cost and my past claim experience.

Could you please guide me - what all other things do I need to check before buying the insurance policy?

Check coverage of both the quotations, access or any additional charges. And always provide all the info in the proposal form, even if you think it is irrelevant for insurance company.