Few problems with my MM (fallen off switch, - wire desoldered)

[What's_nitro?]

Looks like it's just physical stress. Dirt getting in the case/ wires gettiing pulled on etc. If you can solder well it's an easy fix to replace the cap/ wires.

Is it under warranty?

[Marvin]

Sorry, a bit off topic but,

What's_nitro?, Damn your signature. When something says don't and you can click on it, you forget about the n't part

Back on topic:

How hot did the ESC get the last time you ran it? If it (or the negative wire) was hotter than normal, the car being slower is probably something to do with that, rather than anything else.

If you are confident soldering (and/or the warrenty has run out), then try resoldering the -ve wire back onto the board, or if you are less confident with a soldering iron (like me), and know anyone who races 1/10 scale stuff, ask them, as they probably will have had to deal with solder tabs at some point.