Potty Nightmares

I have been trying to potty train Ethan for about a year now. The very first attempt was going great a bm first and then pee pee. Great! Well it went at a steady pace from there but, not any further. Well now that he is 3 1/2 I really need to get the ball rolling faster. The problem is that he won't tell me when he has to go. I ask him all the time I put him on the potty he will go a little bit and do a bm in the training pants. I have tried the potty books, taking him every half hour, putting training pants on and letting him just go in his pants. He doesn't mind the feeling I guess of gushy pants. And sitting in the bathroom for 20 minutes. well, I started taking away toys and putting them in the garage. That got his attention especially when I took away his friend Dino. I found a new game. If he goes potty in the potty he gets to shop for a new toy in the garage. If he goes in his pants we take the toy away. Well, he now begs me to go potty. So, it is working well. I hope to have this potty training wrapped up in a few weeks:} whew!