public partial class Companies
    {
        public int CompanyId { get; set; }
        public string Name { get; set; }
        public string Description { get; set; }
        public string Tel { get; set; }
        public string Logo { get; set; }
        public int? Owner { get; set; }
        public int? Address { get; set; }
        public int? Publish { get; set; }

        public ICollection<Cars> Cars { get; set; }
}
public partial class Cars
    {

        public int CarId { get; set; }
        public string Manufacturer { get; set; }
        public string Model { get; set; }
        public string Year { get; set; }
        public string Description { get; set; }
        public decimal? Price { get; set; }
        public int? CarCatId { get; set; }
        public int? CompanyId { get; set; }
        public int? CharacteristicId { get; set; }

        public ICollection<CarImages> CarImages { get; set; }
}

public partial class CarImages
    {
        public int CarImagesId { get; set; }
        public string Image { get; set; }
        public int? CarId { get; set; }

        public Cars Car { get; set; }
    }

var compInfo = _context.Companies.SelectMany(cr => cr.Cars.SelectMany(i =>i.CarImages.Where(car => car.CarId == car.Car.CarId))).ToList();

var compInfo2 = _context.Companies.Include(a => a.AddressNavigation).Include(cr =>cr.Cars.).FirstOrDefault(c => c.CompanyId == id);