The Export Control Organisation is responsible for assessing and issuing export licences for specific categories of "controlled" goods. A wide range of items fall under Export Control Legislation. As well as obvious products such military products, firearms and ammunitions, many products which have a potential "dual-use" in nuclear, chemical or communications applications are also potentially subject to export controls.
It is unlikely that an export licence would be required for cars and components, but it is always best to check with the Export Control Organisation
A very good overview and introduction to Export Controls can be found on the Export Control Organisation's website:
You will need to check , for each of the countries that you are looking to export, what the local import regulations are - other contributers have mentioned pre shipment inspection, conformity to local standards and possible restrictions on the age of second hand vehicles.
Some countries levy quite high import duties and other taxes on imported vehicles. To find out what import duties exist, you can then look on the EU Database of third Country Import Duties. This will tell you what the rate of import duty is for products imported from the EU into a "Third Country" e.g. Kenya http://madb.europa.eu/madb/datasetPreviewFormATpubli.htm?datacat_id=AT&from=publi
If you need help in this please do not hesitate to contact me.