One of the weaknesses of the Mahindra XUV 3XO is poor boot space for its class, and hence we would rule it out since boot space is one of your requirements. The Kia Sonet has the maximum boot space, but the Hyundai Venue is almost as good and overall is a better car after its recent upgrade a few months ago. You can opt for the 1.0 turbo petrol with the DCT option, which will serve you well both in the city and on the highway. Since all the options you have listed are compact SUVs, rear seat space is not the best, and though three passengers are manageable, it will be a tight squeeze.