I think they may have been talking rubbish.
Eibach 30mm Pro Lowering Suspension Springs
Golf 4 1.8, 1.9TDi 66 + 81 kW Manual, 1.9SDi, 2.0 FWD 08/97>
£141.00 inc. VAT
Eibach 30mm Pro Lowering Suspension Springs
Golf 4 1.8T, 1.9TDi 74 + 85 kW Manual, 1.9TDi 66 + 81 kW Auto, 2.3 V5 110 kW Manual FWD 08/97>
£141.00 inc. VAT
Eibach 30mm Pro Lowering Suspension Springs
Golf 4 1.9TDi 96 + 110 kW Manual, 1.9TDi 74 + 85 kW Auto, 2.3 V5 125 kW Manual, 2.3 V5 125 kW Auto FWD 08/97>
£161.00 inc. VAT
Eibach 30mm Pro Lowering Suspension Springs
Golf 4 2.8 V6 4motion 01/99>
Given the different springs on offer for engine types, correct springs will be a 30mm drop