To book a 7-seater car in Goa, it is important to note that the Maruti Suzuki Wagon R is typically a 5-seater vehicle and not available in a 7-seater configuration. However, if you are looking for a similar category of car, here is the general process for booking a self-drive car in Goa:

1. **Choose a Rental Service**: Select a reputable self-drive car rental service in Goa, such as GoGoa Car Rentals or Triplina.

2. **Select the Vehicle**: Since the Wagon R is not available in a 7-seater version, you may need to opt for a different 7-seater vehicle if available. However, for a Wagon R or similar, you can proceed with the booking process.

3. **Check Availability and Pricing**: Prices for a Maruti Suzuki Wagon R can start from ?1200 per day in low season and up to ?1800 per day in peak season. Ensure the vehicle is available for your desired dates[5>.

4. **Book the Vehicle**: You can book the car through the rental service's website, live chat, or by calling their customer support. Specify your pick-up and drop-off locations, which can include Goa Airport, railway stations, or selected bus stops[3).

5. **Provide Necessary Documents**: You will need to provide a valid 4-wheeler driving license and an original photo ID proof for security purposes. A security deposit of up to ?5,000 may also be required[5).

6. **Inspect the Vehicle**: Before taking possession of the car, inspect it thoroughly and report any existing damage to the rental company to avoid any charges upon return[5).

7. **Adhere to Terms and Conditions**: Ensure you follow all traffic rules, use seat belts, and avoid drinking and driving. The vehicle should be returned in good condition and within the specified return time[5).