It depends. If you're looking for a project car to tinker on and don't mind potentially spending a lot of time under the hood, under the car, and at the parts counter, it might be a winner. If you're looking for inexpensive transportation, run away.

I'll also add my stock advice on the purchase of the W140 chassis: Hold out for an S600. After all, if you're going to have an ugly maintenance intensive fuel sucking pig, you may as well have a fast ugly maintenance intensive fuel sucking pig.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.