Can I sell a modified vehicle with Motorway?

Yes. However, modifications may have an impact on the number of offers you receive, as some dealers will only purchase standard vehicles. 

When selling a modified vehicle, you will be asked to provide documentation that confirms that the modifications were carried out professionally. If you have the original components from your vehicle - and can make them part of the sale - this may give you further options, as some dealers may wish to purchase your vehicle if they can return it to its previous condition.