This border carries much less traffic than the crossing at Singapore. However do expect delays at the usual peak times and on public holidays. Leaving Malaysia At Bukit Kayu you can pick up copies of the Thai immigration documents. For a modest fee, these can be filled out by petition writers if you feel you need this. You can also pick up the Thai documents at the border itself as you approach Thai Immigration.
Processing takes no more than a couple of minutes.
When you come back from Thailand however expect an inspection of the boot, some questioning and possibly the need to have your luggage x-rayed. As you drive up the road into no mans land, you will come to a Malaysian police checkpoint. Here the police will inspect registration documents. Being a Singaporean registered car, we have been stopped every time. Make sure you have your log card and identification ready.