Diapet has modeled the G1, G3 and G4 Preludes over the years in 1:40. As typical with other Diapets, the Preludes focus on operating features rather than fine castings or details.

The G1 Preludes were available in a few colors. Of note are the fact that the trunk, hood, doors and even moonroof operate! The doors have windows that are half down with a finished door inside (a feature not found on later Diapet Preludes). The underside of the hood has the sectional details. The engine is finished in chrome. They come in a box depicting a bronze colored car.

The G1 Prelude here in yellow has a black interior. 

Here is a gold version of the car.

And a blue one

 The G2 Preludes are quite rare - though they do have a lot of detail that were phased out of the later generations. The red one and white one is in the collection with their respective G-26 labeled boxes (depicting a red car). The hood hinges in front as in the actual car - revealing an engine finished in chrome. The moonroof, hood, trunk and doors all operate.

The G3 Preludes 2.0Si 4WS (1988 model) were very crude in its casting - mainly because Diapet casted the entire door including the window frame as one piece.  The moonroof no longer operates.  Diapet's G3 Preludes came in 2 variations: the G55 and the SV20.  The G55 has chrome wheels and engine while the SV20 has white wheels and a grey engine. Tires are rubber compared to the plastic tires on the G1 Diapet Prelude. On the G55 variation, the moonroof has a casted border but the moonroof itself is a black decal.  However, the hood trim and side molding is painted black. The underside of the hood has the sectional details.

Here, the black G3 Prelude (SV20) comes with white wheels.

Here's an Red G-55 version with chrome wheels and extra black details with no box.  The tires are cracked.

Here, the white one (G-55) has chrome wheels

And finally, a rarer silver.

The G4 Prelude had a much finer casting than the G1  and G3 Diapet Preludes but it looses the window frame of the door. The Diapet G4 Prelude comes in both a 2.2Si (SG-11) and Si VTEC (SV-34) packaging. It also loses an operating trunk. The underside of the hood has the sectional details. The engine is finished in chrome. The only noticeable difference between the 2.2Si and the Si VTEC are what tires came on them - the Si VTEC has nicely detailed and more realistic rubber-like Bridgestone RD-209 tires while the 2.2 Si have more plasticy tires with no markings and badly formed tread design.

2.2 Si (SG-11)

Si VTEC (SV-34)

Si(SG-11)

Yellow Si VTEC (SV-34)

Black Si VTEC (SV-34)

The tire differences between the 2.2 Si (left) and the Si VTEC (right)