i rented at car from Jucy car rental. It was fast process and the car is in good condition.
1) sydney - central tilba
use route lawrence hargrave dr instead of princess motorway. You will enjoy more scenaries and will drive through Sea Cliff Bridge. you can stop at CATHEDRAL ROCKS, BOMBO HEADLAND QUARRY, KIAMA BLOWHOLE
It was a mistake the stay was too far staying which is at central tilba.. as i didnt know there are many places that I wanted to stop! so probably you can over night at ULLADULLA.
2) Central Tilba - lake entrance
using tathra bermagui rd route. passing by bermagui, Cuttagee, Mogareeka, Merimbula, Eden
walk around tilba town. drive tru wallaga bridge lake, the blue pool (no time to go)
same here journey too far. probably you can stay at Eden
3) Lake entrance - Traralgon
not much to see in between the journey because i wanted to go Walhalla and catch a train at Thompson to up to Walhalla. Drive down stay a night a Traralgon.
Many might choose all the coastal drive like going to Wilsons Promontory National Park but half way i prefer some mix with inland route so i choose traralgon.
4)traralgon - Melbourne
I went to REDWOOD FOREST, YARRA VALLEY CHOCOLATERIE & ICE CREAMERY (I didnt go)
Metung,Mallacoota, Narooma, Jervis Bay. These are some nice place to overnight..
I think my explanation is very brief because Im sleepy now.. hehe.. if you have time you can spend more days..
you can google the destinations and drag your preferred route and you will know how long is your journey. if you have any queries, I will try to explain in my minimal knowledge.

want to know.. for car rent, u pick up in sydney & drop off in melbourne isit? any additional fee? coz i heard becoz of interstate, rental companies dont want to accept, or charge too high.