Mopar let the Hellephant out of the box; Toyota confirmed the 2020 Supra’s debut; and we took a spin in the 2018 McLaren 570S Spider. It’s the Week in Reverse, right here at Motor Authority. Mopar brought back the 426-cubic inch Hemi V-8 known as the “elephant engine” this week, only this time it’s supercharged with bits from the Demon and…