Regarding driving, Things to be aware of: it's pretty hectic in Kenya, with the rules of the road being a guideline only for most drivers, poor training and road discipline adding to the mix. The main issues are poorly judged overtakes and sometimes undertakes, (he volume of slow moving trucks doesn't help), public service vehicles stopping/pulling out unexpectedly, vehicles pulling out into traffic without giving way, badly ridden motorbikes (lots of these especially in towns and cities).  Drivers tend to ignore traffic lights and speed limits.
If you drive defensively, keep distance from motorbikes and public service vehicles and fully concentrate expecting the unexpected, its manageable.
There are lots of serious accidents, which happen particularly at night, so plan journeys in daylight.
There is a lot to get used to, especially if you arrive and jump into a car, rather than experiencing the roads as a passenger first. We also drive on the left here (like the UK), so if you aren't used to this, then that adds a layer to everything. Having said that it's much easier away from town centres.Â
Roads everywhere have massive speed bumps around schools, and communities and these aren't always marked well. Some of the speed bumps are large enough to scape the underside of a saloon car.
Police check points; they mainly stop public service vehicles and trucks, but sometimes cars too - be mindful of corrupt officers who may look for an excuse to extort a bribe. Always have your passport and driving licence to hand - you will be asked for both as they check your date of entry to ensure that you are within the 3 month limit for driving on a foreign licence. If you want to drive for over 3 months, you will need to apply for a Kenyan licence.
Google Maps does a decent job regarding directions.Â
You will need a 4 x 4 vehicle for exploring the national parks Masai Mara for example has banned 2WD vehicles.
Safety. As for above regarding windows and doors. In heavy urban traffic, it's not unknown for an opportunist to reach into the car and snatch mobile phones etc. There are certain areas where it's not advisable to drive at all - locals will be able to guide you on this. There tends to be a lot of hawkers and people begging at places where traffic is heavy. If you decide to give a person something, do it just as the traffic moves off, then you wont be surrounded by people.