Character placement is perfect, however it feels a bit too "plain" for a racing livery, sponsor placement is a bit on the scarce side, too.
Also I believe you left nothing on the bonnet, correct... ? If that's the case you'll need to populate things a bit, it just looks too simple, lacks of effort, even.
Vinyl can use a bit more of complexity, plus some more sponsors as well - you'll need good composition, that's for sure.