I used 3M VHB double sided tape but you have to wipe wax and grease on the area first it will fall off. You should wipe wax and grease over it no matter what you use, because the plastic is oily and nothing will stick to some thing thats oily.
I got a few std parts from my upgrade
RB25DET S2 Plemun and runners $120 (Plenum SOLD)
RB25DET S2 L-Shape crossover pipe with bov mount $35
RB25DET S2 Turbo Heat sheild $10
RB25DET S2 Std dump front pipe $15
Hybrid Intercooler 600x300x76 cooler for Skyline 32/33/34 only done 1500k's since I bought it
The pic is of it on the car now. SOLD
Ill add a few more parts later on
Ive got a new high mount and turbo etc etc. And I decided to get a new bonnet made up for heat reasons. So I bought a second SII skyline bonnet and I'm putting the Ford BA lump in the middle of it (Yes I said Ford) but at the front I'm going to have it sit up by 25mm so I have a scoop at the front and then divert it over to the turbo some how (I haven't worked that one out just yet) and at the rear have it sit up by 30mm across the back to get rid of the hot air. Ill post some pics up when I have it fiberglassed on there to give you an idea.