Okay, so your first problem seems to be that you're not getting your input correctly. I've added strictand warnings and the commensurate mystatements, and then used Data::Dumperto show what you're collecting:

#!usr/bin/perl
use strict;
use warnings;
use Data::Dumper qw(Dumper);
my @car_list = ();
open(INPFIL,"cars.dat") || die("Couldnt open the file \n");
while(<INPFIL>)
{
    if(/^\s*CARS\s*[A-Z]/)
    {
        my ($car)=$_=/^\s*CARS\s*(\w+)/;
        push(@car_list,$car);
    }
}
print Dumper @car_list;
exit;
[download]

The output shows you're collecting a bunch of 1s:

S:\Steve\Dev\PerlMonks\P-2017-05-29@0722-Cars-Arrays-Groups>perl cars0
+.pl
$VAR1 = 1;
$VAR2 = 1;
$VAR3 = 1;
[download]

Nothing else matters until you fix that. This is a variant of what we used to, in the profession, call "garbage in, garbage out".

Now, I could tell you why you're collecting 1s instead of car manufacturers, but it's a good exercise for you to take a stab at explaining why.

What's your best guess(es)?