I contacted Michael at Bali Holiday Secrets to get a transfer from Gilimanuk Harbour to Seminyak. He organised a driver (Putu) who was great - he contacted me via Whatsapp beforehand, then met us as we exited the terminal, had a nice car and drove very well (and stopped off at a convenience store for us to grab snacks and have a toilet break). The price was also super-reasonable considering the transfer ended up being like 4 hours. I then contacted Putu numerous times for further drives, and if he couldn't do it, he had other people he organised for us. Would definitely use Bali Holiday Secrets again.