By JOHN D. STOLL (16:49:50 July 01, 2003) Just about the time Bimmer buyers are getting used to the looks of their new 2004 5-Series, Cadillac will open the next chapter of its assault on German engineering by introducing the redesigned Seville. Expected in showrooms late next year, the sedan adopts Caddy’s three-letter designation as an STS and the Seville moniker goes away (DTS takes the DeVille’s place in 2006 to make the changeover complete). One GM official told us to think of the 2005 STS sedan as a stretched-out, more sophisticated CTS that will be positioned squarely against the 5-Series, much like the CTS goes after the 3-Series. It also adopts the CTS’s rear wheel drive setup, magnetic ride control from the current Seville and a performance tuned suspension. In addition to sharing Caddy’s Sigma platform with the CTS and SRX sportwagon, the STS will get Cadillac’s new 255-hp 3.6-liter aluminum V6, also available in the CTS and SRX. Cadillac’s newly developed 320-hp Northstar V8, as found in the XLR roadster and SRX, will give the STS serious power, and a performance oriented, 400-plus-hp V-series is slated to come out after launch, joining V versions of the CTS and XLR. As for taking a shot at the 5-Series, the public’s chilly response to the 2004 BMW 5-Series styling is seen by GM management as something that potentially opens a door for the STS. The strong positive response to the CTS and the move to rear wheel drive will also lend credence to the effort.