Been to Singapore GPs few times myself, so my first question, what's your budget? If money not an issue, paddock passes

Cheap and value for money: Bay Grandstand (but I think no longer available, not sure) because of the MBS/Singapore skyline view and fireworks after the race. Also best place to see the driver parade. Race itself is quite meh but one of the cheapest tics available.

Suggested: Turn 2 grandstand. My fav place to sit. Price is quite atas, but for me it's the best place for first lap action and potential overtake. Don't take the low seats, the fence will disappoint you. I prefer better overall vantage so usually like row 15 and above.

Overrated: Main grandstand. I know alot of ppl like the main grandstand but what you see is just car zomming pass at 300km/h. Totally not worth for me unless you want to see pit action and podium celebration.

If you want to watch concert afterwards, then Padang grandstand because it's the nearest. But you'll never get to the front area because people are camping there just for the concert itself. Many ppl also suggest Stamford but I haven't tried. From the photos it looks very average.

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For pre-GP weekend event, follow the teams and sponsors to see what kind of events pre-GP weekend events they are hosting. Some are free, some are paid and some only for invited guest. As for the GP itself, the main event is always the concert.

Food wise, google or ask around what's good in SG. Circuit food is expensive, taste like shit and super long queue. I buy the cheapest food just to fill my stomach lol.