Instantiating an ICollection of some interface objects: Compiler Error

My code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CarOwnership
{
    public interface ICar
    {
        string Make { get; set; }
        string Model { get; set; }
    }
    public class Person
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public ICollection<ICar> CarsOwned { get; set; }

        public Person()
        {
            //This assignment gives a compiler error:
            //Cannot implicitly convert type 
            //'System.Collections.Generic.List<CarOwnership.VintageCar>' to 
            //'System.Collections.Generic.ICollection<CarOwnership.ICar>'. 
            //An explicit conversion exists (are you missing a cast?)

            this.CarsOwned = new List<VintageCar>();
        }
    }

    public class VintageCar : ICar
    {
        public int Id { get; set; }
        public string Make { get; set; }
        public string Model { get; set; }
        public decimal Cost { get; set; }
        public string Remarks { get; set; }
    }
}

Why does the assignment

this.CarsOwned = new List<VintageCar>();

gives the compiler error?

Is an explicit cast the only way out?