Some beginner-friendly upgrades that I could think of off the top of my head and suggest are a better intake kit and some better form of an exhaust setup. As for the ground wires, sadly to say, they don't add 5 hp, BUT, they do make your electrical system a lot better and more efficient. I speak from experience. I own a gen. 2 Camry, and I replaced the stock ground wires with 4 gauge wires (basically the same as battery cables:p ). Overall, all the little lights and such seem to light up brighter and better. Now I haven't drug out any testers or anything like that to see if it "officially" improved anything. But from what I can tell, I've seen an improvement. Anyway, I hope this helps some.
Oh yeah...I managed to get my gen. 2 Camry up to around 110 mph late late one night (or should I say, early early in the morning, like at 1 something am.) on a really long backroad. I'll admit though that I got lucky to have not gotten a ticket! I too tried to take a picture of my speedometer while going that fast, but I used one of those cheap-o Wal-Mart disposable cameras and when I got the film developed the picture utterly sucked and you couldn't see anything cuz it was one giant blur, so I didn't bother posting it.
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It's not what car you have, it's what you do with it that matters.

Packing your lunch in a paper bag-$5.00
Eating your lunch you bought on an airplane-$50.00
Losing your lunch from the airplane's cuisine, but not having a paper bag-Priceless
For everything else, there's paper bags!