KBB and Edmunds are in the back pocket of dealerships / car manufacturers and are basically shills for them and have very little real research to back up their values. They don't go to the extent that a Hagerty or NADA would. They also fail to consider the '98 is now a classic and falls under a different valuation / category. They fall for the same misconception as many including dealerships / sales managers etc., that newer = more valuable / worth more than previous year models. It simply doesn't work that way. The '98 made it's mark and the rest of the years are just assembly line cars for all intent and purpose.BTW - Kelley Blue Book lists the 98 at $10,300 and the 04 as $13,000. This was for the standard coupe with 90,000 miles and good condition. I didn't check any other years, just those two
As with any car that makes its mark, especially in a radical new design, the following years are just production / assembly line no added value continuations on the one car that got the distinction (whatever that may b, whether a radical new design or major development worthy of setting it apart). Thereafter just production line vehicles with no inherent separate value.
I only use NADA as a seller or buyer to ensure both get an accurate value in a deal and be sure both are assured an accurate valuation. Hagerty has the '98 at $20Kin #2 conditiion / $26K Concours. There's a Classic Cars only company (nationwide locations) that's taking my 'vette on consignment and thEy gave it a #2 rating based on Hagerty and other guides that they used.
They may also pick up my 1997 Lincoln Town Car Cartier which is actually nicer than one they recently had listed (it's sold), that was similar to mine exterior and interior color wise, but where theirs had a moon roof, mine has the very expensive 8 window special order chrome wheels with full size matching chrome spare. Not many people ordered these. Prohibitively expensive, but I also had one same as theirs with moon roof, but sold it fairly soon after I bought it due to lack of headroom. Theirs sold for $12,999. They valued mine at $10K, but it does have a pretty bad looking scratch through the paint on the top of the passenger side fender (however the heck that happened...) That's all that's wrong with it. It still smells / looks like a new car inside and out, and was a near flawless proverbial little ol' lady car except for that scratch. I flew out to Mobile, Alabama to buy it. She only drove it to church and to the market. She was too old to drive it anymore.
Her husband owns a dealership so it was meticulously maintained. Only 63K mi when I bought it 5 years ago and has 77K mi right now. The classic car place figures they can net me $5500. That'll work. Got it for about that, plus the airfare, hotel, for myself and nephew, (but I look at that part as a mini vacation). Drove it back to Santa Fe, N.M. like floating on a cloud. I have another 1997 white Signature with 182K that I drive daily and bought it 18 years ago. Looks almost as new as the Cartier. Got it from an estate sale with 53K miles on it: