Car suits/nomex: Molecule. Nothing works better yet still maintains the integrity of the product. Have 4 suits and Molecule works best on all of them.
Kart gear: as weird as this sounds I have more recently found myself using tide liquid laundry detergent, the kind without any bleaches. Wash on cold/cold and it’s been working great on my alpinestars suit.
Shoes/helmets: Hard to beat Molecule Refresher. It’s so good we use it in hockey skates, casual shoes, you name it. Insanely good product, 10/10!
Also- everything washed after every day at the track. Letting oils and crap sit in the suits will only trap them in fabrics.