how to filter request both modelname and districtname in Laravel 5.6?

working with laravel 5.6 and mysql. I have following table name as vehicles

id  name  categoryname  brandname    model     districtname
1   juy   car           toyota       121       coba
2   gty   van           nissan       caravan   natai
3   bgh   car           bmw          520d      zenso
4   hyu   van           ford         max       mizuri
5   nhj   car           toyota       121       nakaga
6   gtr   car           toyota       corolla   wassa
7   gtr   van           nissan       caravan   goa

I have following controller function to filter request modelname,

$vehicles = Vehicle::with('uploads')
                ->when(request('modelname'), function ($query, $request) {
                    return $query->where('modelname', request('modelname'));
                })
                ->orderBy('adtype','DESC')

but now I need filter as above request both modelname and districtname also, how can I configure it as above controller?

via Chebli Mohamed