The Champion Locost and the Haynes Roadster share similar chassis dimensions to the original Lotus Seven. In contrast to the Locost's space frame-inspired chassis, the Locust uses a ladder chassis and a body constructed from plywood skinned with aluminium. The Locost is not to be confused with the similarly named Locust which is also a Lotus Seven-inspired car. In the UK this entails an IVA test and registration with the DVLA. Approximately 10 (as of April 2010) cars have been completed and passed by their countries government for use on the road. Roadsters are becoming an increasingly popular choice over the Locost due to the more plentiful donors and the more advanced suspension. The book contains alternative suggestions for incorporating other donors including a BMW E36, Mazda MX-5 and also motorcycle engines. The suggested donor car is a Ford Sierra. Other additions to the original Locost design include information for fabricating a rollbar and advice on using engines with fuel injection. Additionally, the car was designed using CAD software, eliminating the measurement errors inherent to the original design. The subject car differs most significantly from the original in that it has an independent rear suspension. Ron Champion's original book was followed up with Build Your Own Sports Car: On a Budget ( ISBN 1-84425-391-0) by Chris Gibbs.
