Have you ever looked closely at a mail truck? (If you’re in the UK, sub­sti­tute a milk float.)

It’s a crude design... The bolts are exposed. The gas cap is vis­i­ble. The cor­ners are square. The wind­shield is nearly upright.

But so what? Most of the time, it trav­els no more than 30 mph. Aero­dy­nam­ics — no need. Style — why should they bother? Speed — next to none. Cushy ride — well, the postal worker might appre­ci­ate better.

The cheap­est car you can buy has a much smoother design. Its inte­rior is way more refined. But its intended func­tion is dif­fer­ent. And car man­u­fac­tur­ers have hugely more com­pe­ti­tion for than mail truck creators.

Take­away: Don’t put too much effort into some­thing that doesn’t need it.