They can serve a summons
anywhere, usually on the address you used to register the vehicle. I just spoke to a buddy of mine, who "is in the business", and he gave me this example, over and above from what I wrote in the previous post, say they don't find you, should you ever be caught up in a road block, they will then immediately arrest you, put you in the bus, and you will spend the weekend in a MAIN prison, i.e Pretoria Central, if you are arrested in pretoria, but should they arrest you at your home or place of business, you will sleep the weekend in the local police cell, I keep saying weekend, because they like arresting people on Friday afternoon's, because the soonest you can see a judge will be the following work day, iow the Monday - "tap that a$$ weekend show"

- I'm also told that they don't usually impound your vehicle when they catch you in a road block, you have to arrange transportation for the vehicle, iow they just leave it next to the road. - But I'm not too sure on this one.
I'm not too sure if you pay the fine that they will drop the case against you. I was however told that they will charge on 10%+ interest Per Month ("High Monthly Interest")
Should you not be arrested even after all that time, and you go and renew you drivers license, they will then revoke you license, and arrest you, and charge you compound interest for the entire duration.
Okay, * takes a deep breath*, depending on the severity of your fine, they might let you pay and you can walk away, but, they also can arrest you there.... e.g if you drove 140 in a 60 zone, you WILL be arrested, no questions asked, but if it was say 66 in a 60 zone, they should let you go. Generally, the 10% rule applies here as well, not only for speedometers. I can't exactly remember the formula, but if you drive 140+ in a 120 zone, that equals warrant for arrest, 130 or so, is just a fine.
Again, I'm no legal eagle, I'm only passing on information, that I was told - I have several sources. Also, the best advice is to seek professional legal advice. My buddy usually does not speak a load of bull, but I did tell him it's for someone on an internet forum, so I don't know if he added stuff to it to make the law more revered.