Can I search in plain language?
Yes — full sentences are the intended input, not a fallback. "A low-mileage estate under 20,000 with a tow bar" works as written; the constraints are read out of the sentence rather than typed into filter boxes.
You can also refine by continuing the conversation. "Same but cheaper" or "something with more light" carries the context of what you already asked forward, so narrowing does not mean re-entering everything. Exact terms still work: quoting a model name or a postcode is respected precisely, because keyword retrieval runs alongside the semantic one.