I think the sign in the photo on this thread may be at the second car park back towards the village, opposite the petrol station.
If you are really want to avoid paying, it is possible to park for free at Ardgarten and walk along the Cowal Way forestry track to join the main Cobbler path.
Luibhean/Ime/Corranich from Butterbridge is a good outing and will be a lot quieter than the Succoth route (apart from the summit of Ime, of course). I don't think you will have any problem parking at Butterbridge, but there are several alternatives back up the road towards the Rest.
Status of the RandBT road is here:
https://trafficscotland.org/tsgms01/