Yup - I'm sure much road rage is caused by pent-up feelings due to self-restraint.
I've even see this after group meditation or teaching sessions, and many parent know the old adage that a kid who is a saint at home is a demon at school, and vice versa, through having to hold it all in.
Of course, as Buddhists we have no self to restrain, a bit like having a dog lead and no dog. LOL
With self-indulgences, a little goes a long way. A small treat can stem larger cravings, unless of course we have eradicated them all.
Most cravings are bad for us as well as restraining ourselves from indulging them. If it is hard to deny ourselves the treats, we have an attachment or even a potential addiction. Best to eradicate the cause of the craving and need less self-restraint.