CMD:v(playerid, params[])
{
    #pragma unused params
    
    ShowPlayerDialog(playerid, 1509, DIALOG_STYLE_LIST, "Vehicle System List!", "1.Park\n2.Repaint\n3.Change Colour\n4.Fix Vehicle\n5.Lock Car\n6.Locate your vehicle\n7.Sell Your Vehicle", "Select", "Cancel"); // You can change the dialogid to anything. you can also add options to the Dialog List.
    SendClientMessage(playerid, 0xEE0000FF, "Select one option from the following in this Dialog!");
}

public OnDialogResponse(playerid, dialogid, response, listitem, inputtext[])
{
    if(dialogid == 1509) // change 1509 to the dialogid of the /v command :D
    {
        if(!response) return SendClientMessage(playerid, 0xEE0000FF, "ERROR: You cancelled the /v !");
        switch(listitem)
        {
            case 0: // First Item
            {
                //You things here
            }
            case 1: // Second Item
            {
                //Your Things here
            }
            //etc..
        }
    }
}

#pragma unused params