{
type = "recipe",
name = "Hauling-Truck",
enabled = false,
ingredients =
{
{"engine-unit", 10},
{"iron-plate", 50},
{"steel-plate", 10}
},
result = "Hauling-Truck"
},

if data.raw.technology.automobilism then
table.insert(data.raw.technology.automobilism.effects, "{type = "unlock-recipe", recipe = "Hauling-Truck"}")
end

I really wish this site pinged me when someone comments. I'll take a look into this as I didn't experience any issues with the truck not being enabled when the research was complete