Lex Vehicle Leasing, which operates a fleet of more than 120,000 vehicles, has pegged the Porsche at 60% of its new value after three years and 60,000 miles, the typical benchmark replacement cycle.
As a percentage of list price, it beats all the other vehicles on the leasing firm's books, although for many fleets looking at wholelife pence-per-mile costs, the list would look drastically different.
In the Lex list, a typical 2.7-litre Boxster will be worth about £19,000 at the end of a contract in three years' time.
Steve Jones, pricing manager at Lex Vehicle Leasing, said: 'This is amazing considering the car has been available since the mid-90s in the UK.
'The Boxster has the all-important Porsche badge on the front, which is important for user-choosers, but the restricted number of vehicles sold each year and the affordability of the entry-level 2.7-litre model has made it hugely popular in both the new and used markets.
'The same goes for the Z4 and X3. Both cars are new to the market – the Z4 has already made a big impact in the sports car sector and the X3 looks like a smaller version of the X5 and has already built up a strong order bank. Both cars are in high demand.'
Fourth on the list is the Mercedes-Benz CLK, which has not been outside the Lex top 10 in three years, while the SLK is placed at number 10.
New entries include the Mazda RX-8 and Audi A4 Cabriolet.
Jones added: 'When you look at the list, there is a clear trend. All the cars have a sporty image, look good, are in high demand and in most cases aren't in mass production.
'All the cars are chosen by higher-level user-choosers, who are less concerned with tax bills, but are more interested in driving a car with the right badge on the bonnet or one that makes the right statement in the company car park.'
|Used car value league|
|Make/model||Value||2004 pos||2003 pos||2002 pos|
|VW Beetle Cabriolet:||49%||5||6||n/a|
|Mazda RX-8:||48%||8||n/a||n/a||Audi A4 Cabriolet:||48%||9||n/a||n/a|