I am trying to create a Test class for my controller extension class.  I have a custom object "Vehicle" that has a Master-Detail relationship to "Opportunity".
With my current Test class, i have 46% code coverage but unable to increase it.  Any help is greatly appreciated!

Extension Class:

public class VehicleExtension {
     Private List<Vehicle__c> vecs;
     Private Opportunity vecopp;
       
     public VehicleExtension(){
     }
  
    public VehicleExtension(ApexPages.StandardController controller) {
        this.vecopp= (Opportunity)controller.getRecord();
    }
    public List <Vehicle__c> getVehicles()
        {
         Id id = ApexPages.currentPage().getParameters().get('id');
         vecs =    [SELECT Name, Make__c,Group__c,Year_Built__c,VIN__c,Delivery_Date__c,Payment_Status1__c,Pickup_Date__c, of_Days__c,
                        Mileage_Requested__c,Internal_Cost_Total__c,Cost_Total__c
            FROM Vehicle__c where Vehicle__c.opportunity__c =:[select Name from Opportunity where Id =:id]];
         return vecs;
        }
   
   public pageReference saveStatusChange(){
        update this.vecs;
        return null;
    }
 }

Test Class:

@isTest
public class VehicleTest{
static testMethod void test() {

    	VehicleExtension fe = new VehicleExtension();
    	List<Vehicle__C> events = fe.getVehicles();
    	fe.saveStatusChange();
    	System.assertNotEquals(null, events);
   
   
      	Opportunity ac = new Opportunity(Name ='tester', CloseDate =System.today().addDays(30),StageName ='Open Request', Posting_Date__c =System.today());
      	insert ac;
    
   		ApexPages.StandardController stdController = new ApexPages.StandardController(ac); 
      	VehicleExtension fe1 = new VehicleExtension(stdController);
       }
}

I am trying to create a Test class for my controller extension class.  I have a custom object "Vehicle" that has a Master-Detail relationship to "Opportunity".
With my current Test class, i have 46% code coverage but unable to increase it.  Any help is greatly appreciated!

Extension Class:

public class VehicleExtension {
     Private List<Vehicle__c> vecs;
     Private Opportunity vecopp;
       
     public VehicleExtension(){
     }
  
    public VehicleExtension(ApexPages.StandardController controller) {
        this.vecopp= (Opportunity)controller.getRecord();
    }
    public List <Vehicle__c> getVehicles()
        {
         Id id = ApexPages.currentPage().getParameters().get('id');
         vecs =    [SELECT Name, Make__c,Group__c,Year_Built__c,VIN__c,Delivery_Date__c,Payment_Status1__c,Pickup_Date__c, of_Days__c,
                        Mileage_Requested__c,Internal_Cost_Total__c,Cost_Total__c
            FROM Vehicle__c where Vehicle__c.opportunity__c =:[select Name from Opportunity where Id =:id]];
         return vecs;
        }
   
   public pageReference saveStatusChange(){
        update this.vecs;
        return null;
    }
 }

Test Class:

@isTest
public class VehicleTest{
static testMethod void test() {

    	VehicleExtension fe = new VehicleExtension();
    	List<Vehicle__C> events = fe.getVehicles();
    	fe.saveStatusChange();
    	System.assertNotEquals(null, events);
   
   
      	Opportunity ac = new Opportunity(Name ='tester', CloseDate =System.today().addDays(30),StageName ='Open Request', Posting_Date__c =System.today());
      	insert ac;
    
   		ApexPages.StandardController stdController = new ApexPages.StandardController(ac); 
      	VehicleExtension fe1 = new VehicleExtension(stdController);
       }
}