I don't think so.
Using your example of a car the conditions that lead to a car would include; the discovery of oil and it's refinement to petrol, the building of roads, the invention of an internal combustion engine, the designer of the car, the market demand for the car, investors that provide venture capital, the sales and distribution process for the car etc.
It's nothing to do with the parts, or concepts. Though conditioning factors have relationships with the end result but not in the way you're talking about.
A car is conditioned, it cannot be unconditioned, ie it cannot just appear out of nowhere and you cannot make it not conform to natural laws no matter how hard you try to view it that way. However it's engine can be reconditioned, but that's a different use of the word.
What you are talking about appears to be one of the common Mahayana teachings on emptiness that talks about nothing having inherent existence and everything being composed of component parts. I'm not sure if they use the terms conditioned/unconditioned in this teaching and you haven't posted a quote showing this, either way it's not how these terms are used in translation of the Pali Canon as far as I'm aware.
For conditioned/unconditioned, I'm happy to use the words sankhara/asankhara. Here are some of the things which Bikkhu Bodhi has to say about it....
"The third major domain in which the word sankhara occurs is as a designation for all conditioned things. In this context the word has a passive derivation, denoting whatever is formed by a combination of conditions; whatever is conditioned, constructed, or compounded. In this sense it might be rendered simply "formations," without the qualifying adjective. As bare formations, sankharas include all five aggregates, not just the fourth. The term also includes external objects and situations such as mountains, fields, and forests; towns and cities; food and drink; jewelry, cars, and computers.
The most important fact to understand about sankharas, as conditioned formations, is that they are all impermanent: "Impermanent, alas, are formations." They are impermanent not only in the sense that in their gross manifestations they will eventually come to an end, but even more pointedly because at the subtle, subliminal level they are constantly undergoing rise and fall, forever coming into being and then, in a split second, breaking up and perishing: "Their very nature is to arise and vanish." For this reason the Buddha declares that all sankharas are suffering (sabbe sankhara dukkha) — suffering, however, not because they are all actually painful and stressful, but because they are stamped with the mark of transience. "Having arisen they then cease," and because they all cease they cannot provide stable happiness and security.
To win complete release from suffering — not only from experiencing suffering, but from the unsatisfactoriness intrinsic to all conditioned existence — we must gain release fromsankharas. And what lies beyond the sankharas is that which is not constructed, not put together, not compounded. This is Nibbana, accordingly called the Unconditioned —asankhata — the opposite of what is sankhata, a word which is the passive participle corresponding to sankhara. Nibbana is called the Unconditioned precisely because it's a state that is neither itself a sankhara nor constructed by sankharas; a state described asvisankhara, "devoid of formations," and as sabbasankhara-samatha, "the stilling of all formations." "
From Anicca Vata Sankhara by Bhikkhu Bodhi.
I don't really buy the idea about conditions leading to the car as being part of the car, such as the discovery of oil etc. since none of those things exist in the present moment. Did you get that from one of Alan Watt's talks? The conditions I'm talking about are the relationships between the component parts which give rise the concept "car" which would otherwise not be there, if say for example all the parts were disassembled and strewn across the floor of the garage. A simpler example is that of a fist. Hold out your hand. Now roll up your fingers to make a fist. Now unroll your fingers again. In both cases there was only your hand, but when you rolled up your fingers you had the added concept of "fist" - something which you are able to make appear and disappear at will. The thing is, literally everything exists in the form of concepts like that.
I dont know what you meant about not being able to not make something conform to natural laws - I don't recall ever making any mention of that.
I am totally happy with the Mahayana teachings - a good deal of it makes perfect sense to me. Remember that Mahayana does not exclude the teachings in the pali cannon, but instead offers certain alternative interpretations. I do however reject the ideas about reincarnation (as opposed to rebirth) and Tantra which I think is complete nonsense. I consider those ideas to be cultural additions.
"The foolish reject what they see, not what they think. The wise reject what they think, not what they see." - Huang Po.