For example:
car Audi = new car();
Is it possible to something like this:
string name = Microsoft.VisualBasic.Interaction.Input
No, you can't. In C# variables must be known at compile time, together with their names...
What you can do is have a collection where to put all your cars... Like:
var allmycars = new Dictionary();
string name = Microsoft.VisualBasic.Interaction.InputBox("Name of new car?", "Add car");
car mycar = new car();
allmycars.Add(name, mycar);
then you can:
foreach (KeyValuePair onecar in allmycars)
{
string name2 = onecar.Key;
car car2 = onecar.Value;
Console.WriteLine(name2);
}