The Kamenari-Lepetane ferry shortens the drive around the Bay of Kotor, while the Sozina tunnel is the fast link between the coast and the inland route toward Podgorica. Neither is a national vignette. They are individual, optional route payments.
Give the two shortcuts their own pocket
The ferry buys distance, not always time
The crossing removes the long loop around the inner bay, but a summer queue can absorb part of the saving. Compare the live traffic, departure flow and the road you actually want to see rather than treating the ferry as automatically faster.
Buy the vehicle class, not a vague car ticket
Ferry pricing distinguishes motorcycles, small passenger vehicles, larger vehicles and combinations such as trailers. A rental car normally fits the small-car category, but a camper or tall van may not. Match the official class before buying online.
Sozina is paid per passage
Monteput's price list puts ordinary two-axle passenger cars within its second category at EUR 2.50. A taller vehicle, trailer or motorhome can move into another category, so use the dimensions in the live list rather than the rental company's marketing label.
There is no Montenegro-wide road sticker
Do not buy an invented national vignette from an unofficial seller. Montenegro charges for specific infrastructure, including Sozina and motorway sections, while most ordinary roads remain untolled.
Keep the road money outside the luggage
A EUR 5 note, a EUR 2 coin and smaller change fit in the front of the daily wallet. They are more useful there than inside a suitcase when the next booth, car park or roadside stop appears without warning.