The term 'alternative to a convertible' can be answered by two crossword solutions: SEDAN (5 letters) and hardtop (7 letters). A SEDAN is a type of car that typically has four doors, a fixed roof, and a separate trunk. It is a popular choice for families due to its spacious interior and affordability. A hardtop is a type of car that has a solid roof instead of a convertible top. It is a more luxurious option than a SEDAN and offers more protection from the elements.