A fleet of about 24 classic Jaguars will drive from Brecon to Carmarthen and Pendine on Saturday to recreate a trip first made in 1957.
It marks 60 years since the prototype of the Jaguar E-Type was test driven in Wales before going into production.
The car was described by motor racing driver Enzo Ferrari as “the most beautiful car ever made”.
It has been credited with “defining the spirit of the 1960s” and was driven by Frank Sinatra and Princess Grace.
The fleet will be flagged off from the Castle Hotel in Brecon by the mayor, Ieuan Williams, and school children.
It will stop in Carmarthen and the Pendine Museum of Speed before travelling back to Brecon.
It is estimated about 72,000 E-Types were built between 1961 and 1975.
In January 2017, a rare example sold for almost £6m.