public partial class Form1 : Form
{

ArrayList data = new ArrayList();
ArrayList nomer = new ArrayList();
FormSearch formsearch = new FormSearch();

public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
string numb = Auto.TryNumber(textBox1.Text);
if (numb != "Fail")
{
int reg = int.Parse(textBox2.Text);
uint pas = uint.Parse(textBox3.Text);
dataGridView1.Rows.Add(numb, reg, pas);
Auto car = new Auto(numb, reg, pas);
data.Add(car);
nomer.Add(numb);
}
}

private void buttonSearch_Click(object sender, EventArgs e)
{
formsearch.dataGridView1.Rows.Clear(); //очищаем таблицу на второй форме

ArrayList search = new ArrayList();

int m = 0;
for (int i = 0; i < data.Count; i++)
{
string s = ((Auto)nomer[i]).numb;
char s1 = s[1],
s2 = s[2],
s3 = s[3];


if (s1=='9')
{
m++;
formsearch.dataGridView1.Rows.Add(((Auto)data[i]).numb, ((Auto)data[i]).reg, ((Auto)data[i]).pas);
}
}
if (m != 0)
{
formsearch.ShowDialog();
m = 0;
}
else
{
MessageBox.Show("Никого не найдено", "Поиск");
}
}
}
}