C-Class

This is a genuinely debated choice and there is no universal right answer — it depends on what you are optimising for.
A new A4 gives you a clean ownership slate. Warranty coverage, the latest feature set, and maintenance costs that are largely predictable for the first several years. There are no unknowns, and that peace of mind has real value in a segment where repair bills can be significant.
A two-year-old C-Class offers more car for the equivalent budget — better road presence, a stronger badge in many social contexts, and features that still feel current. The risk is what you cannot see. Service history gaps, deferred maintenance, or components approaching replacement cycles can turn an attractive deal into an expensive one fairly quickly.
The practical filter is straightforward. Used luxury makes sense when two conditions are met — full documented service history is available, and at least one year of manufacturer warranty remains on the vehicle. If either of those is absent, an extended warranty from a reputable provider should be treated as non-negotiable before signing anything.
Without that safety net, the price difference between new and used tends to narrow faster than most buyers expect once real-world ownership costs are accounted for.