ie, Bribes. The best technique seems to be waiting for a) official boredom, b) more money making opportunities to turn up, eg, tourists c) somebody higher up in the chain to come along, eg, military vs police.

Country Asked for Paid Description
Ukraine €100 €30 Supposedly doing 80kph in a 50kph zone. Possibly true.
Ukraine €40 €20 Not stopping at a stop sign. The trouble was there was a massive truck in the way of the sign, if there was a sign.
Iran Multiool (€30) T-shirt and tea Official at the border kept asking for gifts. Wished we hadn't given him anything after below.
Iran €20 €10 Burly man at the border who we didn't want to piss off too much.
Iran $0 $0 Caught speeding, but let off with a warning :)
Turkmenistan ? $10? Caught speeding as the police put up temporary speed limit signs, in this case 30kph, which was honestly difficult to read.
Uzbekistan $8 $8 This was actually official, I even got a receipt! But it was still ridiculous. I was fined for driving too quickly through the "disinfectant" at the border. There was no way I caused all the puddles that they were pointing at, tbh, I think the team that went before me might have done it, but we both got fined. We didn't stop at the stop sign, a recurring theme.
Uzbekistan ? £1 Kai caught speeding. Let off after trying out speed gun and a misunderstanding about a "gift", Kai insisted on going back and giving him a souvenir pound coin. The policeman did not look impressed.
Tajikistan $10 $10 Passport officials. Stupidly paid without thinking.
Tajikistan $45 $25 Car insurance, or possibly customs. I think $25 was the proper sum, but we were asked for $45.
Tajikistan ? ? Have a feeling that the last two guys that dealt with us wanted something?
Tajikistan $10 $0 Police check at the border. I was going to the car to get some money but they got bored and we just left.
Tajikistan Up to €100 down to $20 $10 Police check point just looking for a reason to take money from us. First they made something up about our visas. We were patient and explained again and again that our visas were ok. When they got bored of that they let Mud-Lab go and started on me and my invalid passport. They were just insisting on $20 when a military guy walked passed outside and they suddenly took our $10 and let us go. I kind of wished I'd snatched the $10, run outside and waved it in their face from the window. But I didn't.
Tajikistan $25 x 2 $10 for both cars. Customs leaving Tajikistan. This seemed to be a tried and trusted scam, telling us that we were missing the customs receipt from entering (see above). It may even be that customs delierately didn't give us a receipt when we entered. We were let off for $10 only when two more teams arrived and were subjected to the same treatment.
Kyrgyzstan $0 $0 Thought I'd mention this as I was very pleased not to be asked at the border as the guards were looking very serious and very dubious about the visa in my old, invalid passport.
Kyrgyzstan ? $10 + 100 Somme ($3?) Kai caught speeding early in the morning, apparently still within the limits of a town.
Kyrgyzstan ? All our old Uzbek money, about $20 Caught speeding again, same day.
Kyrgyzstan ? $10 between two cars Same day. Not stopping at a stop sign, *just* before the Kazakh border.
Kazakhstan $10 $0 Accidentally left border into Kazakhstan and needed to get back in to Kai and the car. Was brazenly asked for $10 but didn't pay and met Kai outside.
Russia 100 Rubles I think, about $3 0 Immigration officer just asked as we were leaving, we acted confused and after a few minutes let us go.
Mongolia $5 100 Rubles, about $3 For disinfecting the car. Other teams said they had to pay $1 and got a receipt.
Mongolia $10 $10 The guy who searched our car (with a very cute dog in a very cute coat) just asked, and we just gave.
Total About $310 About $180