Filigree Racer
Artifact — Vehicle
When this Vehicle enters, you get 
(four energy counters).
Whenever this Vehicle attacks, you may pay . When you do, target instant or sorcery card in your graveyard gains jump-start until end of turn. (You may cast that card from your graveyard by discarding a card in addition to paying its other costs. Then exile it.)
Crew 1
Gaboleps
Rulings
If an effect allows you to pay an alternative cost rather than a spell's mana cost, you may pay that alternative cost when you jump-start a spell. You'll still discard a card as an additional cost to cast it.
(wotc • 2024-06-07)
When casting a spell with jump-start, you must still follow any timing restrictions and permissions, including those based on the card's type. For instance, you can cast a sorcery using jump-start only when you could normally cast a sorcery.
(wotc • 2024-06-07)
A spell cast using jump-start will always be exiled afterward, whether it resolves, it's countered, or it leaves the stack in some other way.
(wotc • 2024-06-07)
Rulings
If an effect allows you to pay an alternative cost rather than a spell's mana cost, you may pay that alternative cost when you jump-start a spell. You'll still discard a card as an additional cost to cast it.
(wotc • 2024-06-07)
When casting a spell with jump-start, you must still follow any timing restrictions and permissions, including those based on the card's type. For instance, you can cast a sorcery using jump-start only when you could normally cast a sorcery.
(wotc • 2024-06-07)
A spell cast using jump-start will always be exiled afterward, whether it resolves, it's countered, or it leaves the stack in some other way.
(wotc • 2024-06-07)