We are visiting from the US and traveling to Vilnius and several cities in Poland in August. We like traveling by car but it's difficult to determine if this is the best option. Other areas we want to see are the Tatras and Krakow., maybe Gdansk. We haven't yet determined if we are going to fly into Vilnius and out of krakow or in and out of Warsaw. Our trip will be 15 days.
It's very easy (and inexpensive) to get around the Polish cities you mentioned by train or even bus (fast trains cover the Warsaw-Gdansk-Krakow route)...having a car would be a plus only if you want to see small towns not well served by public transit. You can even get to Zakopane (Tatras) by bus. The downside of a car is price of gas and parking in cities; otherwise, driving in itself is not that difficult. I would not try to return the car in another country, if you do decide to rent (the drop-off fees will be steep).
Thank you, that is helpful. Gas is very expensive. We do want to go to the beaches in the Gdansk areas so i think we may need a car or taxis for those areas, so we may be looking at car for some of the trip and combining it with public transportation. I don't know if the public transportation system is as good in Lithuania.
The multi-city (open-jaws) flight route seems most logical.
Lithuania doesn't have much international train service and the fastest train connections between Vilnius and Warsaw go via Belarus, which I believe requires a visa. LOT has direct flights on this route.
Do you have other destinations in Lithuania? Direct trains from Vilnius to Klaipeda take 4 hours and make just a few stops. You also might not be able to use the same rental car in both countries, even if you drove roundtrip, so consider shorter rentals where you need them.
We do want to go to the beaches in the Gdansk areas so i think we may
need a car or taxis for those areas
If you mean Sopot, then "no", you don't need a car to get there. Public transport works well in that area.
That's a good point about the rental
Car over the Lithuanian border from Poland. We won't have visas so would a bus be our only option and would we need reservations? We were planning on staying on Augustow the night before so I hope we can catch transport to Kaunas from there. We wanted to visit Klaipeda so we thought we would stay in Kaunas as a base between Vilnius and the coast. Then we will head north to hill of crosses and on to Riga.