You get your nails to the same length, give them a neat manicure, spend an hour polishing them to perfection and even longer leaving them to dry – then ruin the whole effect by splitting one opening the car door.
It's possible to patch the split long enough to allow the nail to grow, by removing any polish, applying a new, clear layer – or base coat will do – and immediately, carefully, sticking a tiny scrap of loo paper over the tear (separate the paper so there's only one thin layer) so it absorbs the still-wet polish and sticks to the nail.
Then apply another layer of polish – any colour – on top. The paper will start to lift after a few days if you apply any pressure to the nail or expose it to water, in which case remove the polish and start again. It may be a pain but it will give your nail a chance to grow to the same level as the others – and filing them down a little will help even the score.