Contains With Invariant Culture, C#

Language: Layout:

//Rextester.Program.Main is the entry point for your code. Don't change it.
//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Rextester
{
    public class Program
    {
        public static void Main(string[] args)
        {
            List<Car> myCars = new List<Car>() {
                new Car() { VIN="A1", Make = "BMW", Model= "550i", StickerPrice=55000, Year=2009},
                new Car() { VIN="B2", Make="Toyota", Model="4Runner", StickerPrice=35000, Year=2010},
                new Car() { VIN="C3", Make="BMW", Model = "745li", StickerPrice=75000, Year=2008},
                new Car() { VIN="D4", Make="Ford", Model="Escape", StickerPrice=25000, Year=2008},
                new Car() { VIN="E5", Make="BMW", Model="55i", StickerPrice=57000, Year=2010}
            };

Console.WriteLine("What term would you like to search?");
            // string search = Console.ReadLine();
            var search = "BM";
            
            var results = string.IsNullOrEmpty(search) ? 
                            null :
                            myCars.FindAll(car => 
                                  car.VIN.Contains(search, StringComparison.InvariantCultureIgnoreCase) ||
                                  car.Make.Contains(search, StringComparison.InvariantCultureIgnoreCase) ||
                                  car.Model.Contains(search, StringComparison.InvariantCultureIgnoreCase) ||
                                  car.StickerPrice.ToString().Contains(search, StringComparison.InvariantCultureIgnoreCase) ||
                                  car.Year.ToString().Contains(search, StringComparison.InvariantCultureIgnoreCase));
            
            if (results!= null && results.Count != 0)
            {
                Console.WriteLine();
                Console.WriteLine("Cars searched with " + search);
                results.ForEach(c => Console.Write("\n{0}\t{1}\t{2}\t{3}\t{4}", c.VIN, c.Make, c.Model, c.StickerPrice, c.Year));
            }
            else
            {
                Console.WriteLine("\nNo Cars found.");
            }
            //Console.ReadLine();
        }
    }
    
    public static class StringExtensions
    {
        public static bool Contains(this string sourceString, string toCheck, StringComparison comparison)
        {
            return sourceString != null ? sourceString.IndexOf(toCheck, comparison) >= 0 : false;
        }
    }
    
    public class Car
    {
        public string VIN { get; set; }
        public string Make { get; set; }
        public string Model { get; set; }
        public int Year { get; set; }
        public double StickerPrice { get; set; }
    }
}

Show compiler warnings [ + ] Show input
Compilation time: 0,16 sec, absolute running time: 0,13 sec, cpu time: 0,09 sec, average memory usage: 23 Mb, average nr of threads: 4