DRS Range:
Firstly, every circuits in iGP Manager have only one DRS range (Main DRS range in real life), however in real life each F1 race circuit has 2 or 3 DRS ranges (Main & Sub) that are usually located towards the end of a relatively long straight. In some of the circuits like Interlagos (Brazil), Baku (Azerbaijan) & Monaco although you've upgraded to Lv.16 to Lv.20 DRS, sometimes still can't overtake manager because the DRS range is too short. Therefore, I suggest that the development team should add DRS ranges into the circuits which are as same in real life and make each F1 race circuit has 2 or 3 DRS ranges. It can creates more opportunity, more overtakes, and also the race will become more entertaining to watch.
Issue of Germany iGP (This's more important I think):
Currently our German GP circuit in the game still remains as Nürburgring, however in real life the German GP circuit has already changed to Hockenheimring. Nürburgring has stopped using to become F1 circuit since 2014, but I think the development team can keep Nürburgring as historical track in the game like Great Britain 09 and rename the GP as "Germany 13". Then, since we don't have Hockenheimring in the game (it's really funny because no one notice that!!), so the dev team can create the circuit of Hockenheimring to replace Nürburgring and becoming our new "Germany iGP" in the game.