Generated by SassMeister.com.

SassMeister-input-HTML.html

<p class="007">bond</p>

SassMeister-input.scss

// ----
// Sass (v3.4.13)
// Compass (v1.0.3)
// ----

@function escape_leading_numbers($s) {
  $first-char: str_slice(#{$s}, 0, 1);
  $found: index('1' '2' '3' '4' '5' '6' '7' '8' '9' '0', $first-char);
  @return if($found, unquote(str-insert(str-slice(#{$s}, 2), "\\3#{$first-char} ", 1)), $s);
}

$name: '007';

.#{escape_leading_numbers($name)} {
  color: red;
}

@each $car in
  bmwwhite
  hondared
  22ltr-porche
  30ltr-cossworth
 {
  .#{escape_leading_numbers($car)} {
    background:url(/img/cars/#{$car}.jpg) no-repeat
  }
 }

SassMeister-output.css

.\30 07 {
  color: red;
}

.bmwwhite {
  background: url(/img/cars/bmwwhite.jpg) no-repeat;
}

.hondared {
  background: url(/img/cars/hondared.jpg) no-repeat;
}

.\32 2ltr-porche {
  background: url(/img/cars/22ltr-porche.jpg) no-repeat;
}

.\33 0ltr-cossworth {
  background: url(/img/cars/30ltr-cossworth.jpg) no-repeat;
}

SassMeister-rendered.html

<p class="007">bond</p>