Saggy suspension is common, especially if it's got the self leveling suspension, best bet is to rip the old unit's out and either get a set from pedders which will have new top mounts springs and shocks, will just bolt straight in, or get a custom set of springs from springcoil and kyb struts and top mounts,there's a thread with part numbers somewhere.
I think Eudm fox's came with a tfo3 turbo so you could bolt on a td04 or 05 or something newer like a vf series turbo on, but will require mapping to avoid it going bang,
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