When I studied Latin in Rome with Fr Reginald Foster, he used to suggest that a good word for a car was autorhaeda, a word in fact used in the Acta Apostolicae Sedis of 1965 when speaking of a visit made by Pope Paul VI to the Basilica of St Chrysogonus in Trastevere. The word raeda (without the "h") was used by Caesar, Cicero and Horace for a travelling wagon with four wheels and the addition of "auto" does not make for too awful a neologism.
In the Rituale Romanum, the blessing for a motor vehicle is the Benedictio vehiculi seu currus. The word currus is normally translated as chariot and reflects the way that people often view their car.
Since one's motor vehicle is more likely to be the locus of one's death or injury than many other artefacts, it does make sense to have it blessed. Above you can see us striding purposefully past the Georgian houses of Victoria Road and here is the blessing of the classic mini:
The blessing given in the Rituale has a typical scriptural reference and calls to mind our journey to eternal life:
Benedictio vehiculi seu currusHere is an English version from the Small Ritual of 1964 which is in parts more of a pious reflection on the text than an accurate translation:
V. Adjutórium nostrum in nómine Dómini.
R. Qui fecit cælum et terram.
V. Dóminus vobíscum.
R. Et cum spíritu tuo.
Propitiare, Dómine Deus,supplicatiónibus nostris, et béne + dic currum istum déxtera tua sancta: adjúnge ad ipsum sanctos Angelos tuos, ut omnes, qui in eo vehéntur, líberent et custódiant semper a perículis univérsis: et quemádmodum viro Æthíopi super currum suum sedénti et sacra elóquia legénti, per Levítam tuum Philíppum fidem et grátiam contulísti; ita fámulis tuis viam salútis osténde, qui tua grátia adjúti bonísque opéribus júgiter inténti, post omnes viæ et vitæ hujus varietátes,ætérna gáudia cónsequi mereántur.Per Christum Dóminum nostrum.
Et aspergatur aqua benedicta.
V. Our help is in the name of the Lord
R. Who made heaven and earth
V. The Lord be with you
R. And with your spirit
Let us pray
Hear our prayer, Lord God, and raise thy hand in blessing over this carriage. Command they holy Angels to be near it, keeping danger far away from all who travel by its means. As thou gavest faith and grace, through thy Levite Philip, to the Ethiopian who sat in his chariot reading thy holy word; so now point out to those who are carried by this vehicle the way that leads to salvation. May thy grace enable them ever to travel to good purpose: and when at last life's journey is over and adventuring is done, may everlasting happiness be theirs. Through Christ our Lord.
The vehicle is sprinkled with holy water.