Just leaving a replay of a shot that made my day here. Shots like this are why I love these games.
||R||p,208,412,1,0,p,178,412,1,0,p,152,401,1,0,p,383,352,1,0,p,384,282,1,0,p,345,315,1,0,p,308,349,1,0,p,310,279,1,0,p,567,316,1,0,p,535,271,1,0,p,555,290,1,0,p,236,404,1,0,p,570,343,1,0|198,316,137,208,27,31,p,170,0,0,7,487,341,121,82,191,68,p,0,0,0,6|147.4|253.55|199|190||
The 'tack' glitch is not limited to the tack shooter, nor is it limited just to the speed boost. You can continue upgrading any tower repeatedly by tabbing over to the upgrade you want, and mashing enter. For amusement, bump the range up to cover the entire maze.
 "Indestruct2Tank"){kind=icon}
 "Gravitee 2"){kind=icon}
 "Bloons Tower Defense"){kind=icon}